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This Vegetarian Breakfast Casserole is just the sort of recipe we need to be enjoying in PJs, at all times of day. Both—meaning the PJs and this recipe—are appropriate at any hour. It makes enough for leftovers, can be prepped well in advance (overnight if you like!), and is easily adaptable to a variety of diets and ingredients.

A pan with a vegetarian breakfast casserole sliced for a crowd with a slice of the casserole on a plate

Whether you are looking for a breakfast that vegetarians can eat, an easy recipe to enjoy all week long, or simply want a lazy-day sort of breakfast that you can eat slices of in your sweatpants at your leisure, savory egg bakes like this one are spot-on.

I consider myself a bit of a breakfast casserole connoisseur, a distinction I owe to my mother.

Whenever my mom has her three adult children—plus our spouses and my nieces—all squished back under her roof, she begins each morning with a crowd-sized breakfast. While the sides might change, a breakfast casserole is the main event.

As a collective, we prefer a savory breakfast casserole like this one over a sweet one (all the more room for a side of Puff Pastry Cinnamon Rolls). They’re almost always egg based, with lots of yummy mix-ins.

Over the years, I’ve shared a lineup of breakfast casseroles like Crockpot Egg Casserole, Everything Bagel Breakfast Casserole, and for the sweet fans, the ultimate Overnight French Toast.

I hope you’re eager for a big breakfast too. This casserole is fully loaded with roasted vegetables and although it’s vegetarian, it is plenty hearty and satisfying— fit for a breakfast feast!

Don’t let the recipe’s title fool you either; this simple vegetarian breakfast isn’t limited only to the AM hours. I love reheating it for fast, healthy lunches and dinners too.

In addition to being vegetarian, this casserole is naturally low carb and gluten free. We love ours with a shower of feta or ricotta baked on top, but it can easily be omitted if you’d like the casserole to be dairy free.

If you love a hearty, delicious breakfast that has the added benefit of being good for you, this casserole checks ALL the boxes. It’s the ideal blend of wholesome and comforting.

Low carb vegetarian breakfast casserole in a baking dish packed with vegetables

How to Make a Delicious Vegetarian Breakfast Casserole

Below, you’ll find my favorite mix of vegetables for this breakfast casserole recipe, but it is by no means the only tasty combination. Feel free to swap these out for others, depending upon what you and your family prefer.

The Ingredients

  • Sweet Potatoes. They’re deliciously surprising! You’ll love how tender and creamy they taste, and they make the casserole especially filling. If you’ve never added roasted sweet potatoes to an egg bake before, now is the time.
  • Mushrooms. Mushrooms add a touch of earthy flavor and satisfying savoriness to this casserole. Be careful not to use sliced mushrooms (buy whole ones and quarter them yourself) or they may overcook.
  • Broccoli. A green, nutrient-packed addition to this vegetarian casserole.
  • Red Bell Pepper + Onion. I love the pop of color that red bell peppers add. Once roasted, both of these veggies bring just the right amount of sweetness to the dish.
  • Eggs. The key ingredient holding casserole together. The eggs will take on all the other scrumptious flavors in the dish and add a heap of protein, making this casserole filling.
  • Milk. I typically use skim or 2%; whole milk would be richer and unquestionably delicious. Use a non-dairy milk, if you need this recipe to be dairy free.
  • Italian Seasoning. A powerhouse of seasoning that’s perfect for complementing roasted veggies.
  • Ricotta Cheese or Feta. Both are excelling pairs for the roasted veggies. This ingredient makes the casserole taste special.
  • Fresh Herbs. Basil, thyme or parsley would all work well.

The Directions

  1. Lightly coat 2 large baking sheets and a 9×13-inch casserole dish with nonstick spray. Toss the vegetables with olive oil, salt, and pepper Evenly distribute the vegetables onto the baking sheets.

    A sheet pan with roasted sweet potatoes, mushrooms, onions, red peppers, and broccoli

  2. Roast the vegetables for 20 minutes at 400 degrees F, until tender. Layer half of the roasted vegetables in the casserole dish.

    A delicious and healthy vegetarian breakfast casserole for a crowd

  3. Beat the eggs together with the milk, garlic, and Italian seasoning. Pour the mixture into the casserole dish, and add remaining vegetables on top. Dollop with small spoonfuls of the ricotta or sprinkle with feta.
  4. Bake for 35 to 40 minutes at 350 degrees F, until the top is golden. Remove, sprinkle with fresh herbs, and serve warm. ENJOY!
Low carb vegetarian egg bake topped with feta cheese

Vegetarian Breakfast Casserole Recipe Variations

  • Dairy Free. Use a non-dairy milk and omit the cheese (or use a non-dairy cheese option).
  • Gluten Free. No changes needed; this breakfast casserole is gluten free as written.
  • Low Carb. Although I adore the sweet potatoes in this recipe, they are higher in carbs than other vegetables; you can swap the sweet potatoes for a different, lower carb option. Roasted cauliflower would be delicious.
  • Potato, Egg, and Cheese. Swap the sweet potato for the same amount of diced Yukon gold potatoes. Sprinkle ½ to 1 full cup of shredded cheese such as cheddar or mozzarella over the first layer of roasted vegetables. (Or try my Healthy Breakfast Casserole with hash browns.)
  • Add Meat. Now, I truly don’t think this casserole needs meat, even if you aren’t vegetarian. That said, if you can’t resist, feel free to swap one of the sweet potatoes for 8 ounces of sautéed chicken or turkey sausage. A breakfast casserole with ham pieces would also be delicious. You can also sprinkle the top of the finished casserole with cooked and crumbled Baked Bacon.

A baking dish with an easy and healthy vegetarian breakfast recipe that's great for a crowd

Make Ahead + Storage Tips

  • To Prep Ahead. Roast the vegetables up to 2 days in advance, then add them to the recipe as directed.
  • Overnight Breakfast Casserole Prep Option. You can also fully assemble the casserole, cover it unbaked, and refrigerate it overnight. Let it come to room temperature while the oven preheats, then bake as directed.
  • To Store. Cover leftover casserole or store in an airtight storage container and place in the refrigerator for up to 3 days.
  • To Reheat. Rewarm the breakfast casserole in the oven at 350 degrees F until hot. You can also gently reheat individual slices of the casserole in the microwave until warmed through.
  • To Freeze. Store leftover casserole in an airtight freezer-safe storage container for up to 3 months. Let thaw overnight in the refrigerator before reheating. I like to wrap and freeze individual slices, then thaw them overnight in the refrigerator for quick meals.

What to Serve with Breakfast Casserole

  • Bread. Breakfast casserole with whole wheat toast or Easy Drop Biscuits would be a delicious, hearty meal.
  • Hash Browns. Breakfast casserole with hash browns is a combination that the entire family will love. (Might I suggest these Sweet Potato Hash Browns?)
  • Fruit. For something healthy and light, try a side of fresh fruit with this breakfast casserole.

More Vegetarian Breakfast Recipes with Eggs

A baking dish with slices of a tasty and low carb egg bake

Recommended Tools to Make This Recipe

Whether you serve it for breakfast, brunch, or brinner, I hope this vegetarian breakfast casserole becomes a well-loved meal in your home too.

If you try the recipe, please leave a comment below and let me know how it goes. I love hearing from you!

Vegetarian Breakfast Casserole

4.77 from 171 votes
A filling and hearty vegetarian breakfast casserole with roasted vegetables and cheese. Low carb and gluten free. Prep it overnight for easy entertaining!

Prep: 15 minutes
Cook: 55 minutes
Total: 1 hour 10 minutes

Servings: 10 servings

Ingredients
  

  • 2 medium sweet potatoes peeled and diced
  • 8 ounces whole cremini baby bella mushrooms quartered (do not use sliced mushrooms or they may overcook when roasting)
  • 1 small head broccoli cut into florets
  • 1 red bell pepper diced
  • 1 red or yellow onion cut into ½-inch dice
  • 1 teaspoon kosher salt
  • 1/2 teaspoon black pepper
  • 3 tablespoons extra virgin olive oil
  • 12 large eggs
  • 1/2 cup milk
  • 1 garlic clove minced
  • 1 1/2 teaspoons Italian seasoning or dried herbs of choice
  • 4 ounces part-skim ricotta cheese
  • Chopped fresh basil thyme, or parsley (optional)

Instructions
 

  • Position racks in the upper and lower thirds your oven and preheat the oven to 400 degrees F. Lightly coat 2 large baking sheets with nonstick spray. Lightly mist a 9×13-inch casserole dish with nonstick spray and set aside.
  • Place the vegetables in a large bowl and drizzle with the olive oil. Sprinkle with salt and pepper, then toss to coat. Divide the vegetables evenly between the two sheets and spread them into a single layer. Roast the vegetables until tender, about 20 minutes, tossing the vegetables on the pan so they cook evenly and switching the pans’ positions on the upper and lower racks once halfway through. Transfer half of the roasted vegetables to the prepared casserole dish and spread into an even layer. Reduce the oven temperature to 350 degrees F.
  • Meanwhile, in a large mixing bowl, beat the eggs together with the milk, garlic, and Italian seasoning until evenly blended. Gently pour it into the casserole dish. Scatter the remaining vegetables evenly over the top, then dollop the ricotta over the top in small spoonfuls (I like to add about 20 to 24 spoonfuls; you want to each slice to have a few dollops, but have them be large enough so that you can actually taste them).
  • Bake the casserole for 35 to 40 minutes, until the casserole is golden on top and the center no longer jiggles when you shake the pan. Remove from the oven and sprinkle with fresh herbs. Serve warm.

Video

Notes

  • TO STORE: Cover leftover casserole or store in an airtight storage container and place in the refrigerator for up to 3 days.
  • TO REHEAT: Rewarm the casserole in the oven at 350 degrees F until hot. You can also gently reheat the casserole in the microwave until warmed through.
  • TO FREEZE: Store leftover casserole in an airtight, freezer-safe storage container for up to 3 months. Let thaw overnight in the refrigerator before reheating.
  • I like to wrap and freeze individual slices, then thaw them overnight in the refrigerator for quick meals.

Nutrition

Serving: 1(of 10)Calories: 188kcalCarbohydrates: 13gProtein: 11gFat: 11gSaturated Fat: 3gCholesterol: 200mgPotassium: 513mgFiber: 3gSugar: 4gVitamin A: 4774IUVitamin C: 71mgCalcium: 123mgIron: 2mg

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Erin Clarke

Hi, I'm Erin Clarke, and I'm fearlessly dedicated to making healthy food that's affordable, easy-to-make, and best of all DELISH. I'm the author and recipe developer here at wellplated.com and of The Well Plated Cookbook. I adore both sweets and veggies, and I am on a mission to save you time and dishes. WELCOME!

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123 Comments

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    1. Hi Cheryl! I’m sorry for any inconvenience the ads caused you. I will certainly keep paying close attention to the number of ads and how they load. I do truly appreciate your feedback!

          1. Thanks so much for everything you do!! Seriously your site basically feeds my family haha!

  1. This sounds so good and I love that you can add in or leave out what doesn’t work for your family. I have a sister-in-law who needs to be dairy and gluten free so this will be a keeper for her. At times, it becomes really difficult to cook for those with special dietary needs but this is such a great idea for any meal. And I love, love, love that it can be made ahead of time. Those are always my go-to recipes.

  2. Roasted vegetables add so much flavor to dishes. I’ll definitely be making this soon. Thanks for your recipe. I pinned it to my casserole board.5 stars

  3. So I made this but did make a few changes, I removed sweet potato, and added spinach to the egg mixture and cheddar cheese on top. It went over very well.5 stars

  4. Love this! The roasted veggies sound amazingly yummy and healthy! Anytime I can squeeze veggies into breakfast I’m happy and the fact you can make it ahead of time is a real bonus!! Thank you for sharing and doing what you do!!5 stars

  5. Excellent recipe, my husband now wants it for breakfast, lunch and dinner! I didn’t have broccoli or red peppers so I added roasted baby carrots, and also arugula and spinach to the wet mix. Also changed the herbs to include a mix of ginger, parsley, garlic powder, onion powder and zaatar.5 stars

    1. Thank you for taking the time to share this kind review, Paula! I’m so happy to hear that you enjoyed this recipe!

      1. Hi Beverly! Za’atar is a delicious blend of different spices. If you’re interested in learning more about it, you can find information here: https://www.bonappetit.com/story/what-is-zaatar.

  6. This is perfect for my vegetarian daughter and her husband: perfect for any time of the day, for a meal or snack.  Thank you so much.

  7. OMG! I served this at a girlfriend’s brunch, (one who is gluten free and has various food allergies), and they were crazy about it. Added a little fruit and we were good to go. Love your vegetarian recipes.5 stars

    1. I just made this casserole for a friends and family gathering and had the same reaction. Everyone took a second piece. I just found Erin; your review convinced me to try something new. Thank you Patricia and Erin.5 stars

  8. Loved all of your recipes I’ve tried so far except this one. It seemed too dense with veggies. The ratio of veggies to egg was too much. My neighbor who’s fighting cancer and I test your recipes on commented that this casserole was sweet. Thinking I put in too much roasted sweet potatoes. When I first pulled out and ate warm I didn’t like it. Having frozen individual servings, I tried one of those today and thought it was better but maybe I’m just hungry!
    Bottom line, think it was just too vegetarian for me.

    1. I’m sorry to hear that this recipe wasn’t to your tastes, Kathleen! Thank you for taking the time to try it and for sharing this review!

  9. I agree.? Thank you for your wonderful, free recipes!  My kids and husband and I love them! I also appreciate the way you present your content.  It is very soothing  to me when I leave my corporate grind and get lost in a recipe on your website.  Keep up the good work.????

  10. Love the vegetarian dishes! Your recipes are tiding us past the q session here, much appreciated!5 stars

  11. Erin I can’t thank you enough for being so kind in offering us your recipes. …and thanks to all who offer their twists on how they prepare the recipe to meet their tastes or dietary concerns.  What I can’t stand is those few that find it necessary to be so quick to be negative. Thank God there are more appreciative fans than the former.
    PS  could those that may find this to be too “veggie” just add more eggs and milk?

  12. I was looking for a breakfast recipe and this looks perfect. I will be trying it soon. Thank you so much for your recipes. I look forward to your emails and Instagram posts each day. Recently I was fascinated with your sourdough bread starter project. Hope to hear more about that. Great job Erin!

    1. Thank you SO much for sharing this kind comment, Chrissie! I hope you love the recipe if you try it!

  13. This recipe looks so much filling and delicious. I plan on making it. Can you tell me If I can make this in a 13 inch by 9 inch non stick baking pan ? Thanks

    1. Hi Gayathri! I haven’t tried the recipe in a nonstick baking pan, but you could experiment with it. If you decide to try it, I’d love to hear how it goes!

    1. Hi Cheryl! You can freeze the casserole in an airtight freezer-safe storage container for up to 3 months. Let it thaw overnight in the refrigerator before reheating/serving. I hope this helps!

  14. The whole family loves it! I switched out the vegetables for what I had in the fridge, but that’s why it’s such a great recipe, it’s very adaptable!5 stars

  15. Erin, I just made this veggie casserole for a friends and family brunch. It was devoured. The flavors were perfection and so easy to make the day of our gathering. Everyone loved it and my son took home the only remaining piece. I am not a confident cook, so the quick video, and easy to follow instructions made me feel more confident. Everyone loved the flavors; we opted for thyme as the additional fresh herb and feta cheese. Next time, I will try the ricotta. I divided the salt/pepper between the roasted veggies and the egg mixture. Every measurement and direction was spot on. I served the casserole with a fresh fruit salad and blueberry muffins. If I make this for my veggie niece as a lunch, I would serve a side salad. Nothing else is needed which makes entertaining a snap. I plan to make this for our next family holiday breakfast or shower. Hint: to save time, I cut all the veggies the night before. The day of my party, I roasted the veggies while making the egg mixture. It was so quick and easy. Thank you Erin. I am thrilled to have found you and I’m eager to try your future recipes.5 stars

  16. This was a great meat-less dinner! I like that it’s a great way to use up veggie leftovers, and now that I’ve made it following your recipe, I feel more confident that I can throw other veggies in there, too. Thanks!
    Fyi, I made a half recipe, and my husband & I gobbled it all up (with a litttttle help from a toddler).5 stars

  17. Hey Erin, I’m super excited to make this casserole for my birthday brunch on Sunday. I’m planning to switch the sweet potato for cauliflower; can I use ist the same way as described in the recipe?
    Greetings from Switzerland!

  18. Love this recipe! Thank you so much. I’m making this ahead of time and want to reheat. I figure 350 but how long do you think. Should I cover when reheating?5 stars

    1. I’m so happy that you enjoyed it, Diane! Thank you for sharing this kind review! You’ll want to rewarm it until it’s heated through, and you can certainly cover it if you’d like.

  19. Made this for Christmas brunch. It was a hit. I added a little sharp cheddar on the first layer and used Yukon gold potatoes. Also added more Italian seasoning. My son said it was one of the best vegetarian dishes he’s had and he’s been a vegetarian for 8 years5 stars

  20. Holy yum. So I didn’t have very many veggies on hand. But I used broccoli and red peppers. And for the cheese I used Gruyere….I will totally be making this again! More veggies next time. Haha. But yum.5 stars

    1. Hi Hannah! I’ve only tested the recipe as written, so you’d be experimenting. If you decide to try it, I’d love to hear how it goes! For an egg white only recipe, check out this Egg White Frittata recipe.

  21. Vegetarian breakfast casserole is great … tasty, satisfying … a ‘keeper’ recipe …thanks5 stars

  22. Do the sweet potatoes get cooked with the roasted veggies or just added to the base of the casserole?

    1. Hi Chris! You’ll roast the sweet potatoes with the other vegetables. I hope you enjoy the recipe!

  23. Hello! This recipe sounds so good! I’d like to prep the casserole the night before I need it and then fully bake it the day-of. Do you think the roasted veggies sitting in egg overnight will turn out well when I bake it the next day? Thanks!

    1. Hi Megan, Under my Make Ahead + Storage tips in the blog post there are details for an overnight prep option. Hope that helps!

  24. Changed out broccoli for summer Squash and ricotta for Feta. Delicious! I’m going to try the ricotta next time!5 stars

  25. I made this for a Women’s Fall Festival at our church. We had four different casseroles. This veggie casserole was a big hit! I was hoping to take some home for the next day’s breakfast but it was all gone! I will most definitely will be making this again!!!5 stars

  26. This looks delicious! My family is not a big fan of roasted broccoli. any substitution suggestions? Would zucchini or sautéed spinach work?

    1. Hi Susan! I’ve only tested this recipe as written but I’ve had other readers use squash with great success! If you decide to experiment, let me know how it goes! Hope you enjoy it!

  27. Great recipe, Erin! Thank you! Super tasty and easy – and gluten-free to boot! I will make this one again and again, mixing up the ingredients so that it is new each time. I halved the recipe, because it’s just two of us here – and it was perfect! Breakfast and leftovers!5 stars

  28. This recipe looks wonderful. But it’s too much for my needs…if I cut the recipe in half, do you think I can bake it in an eight-inch square dish? Also, any thoughts on not using the mushrooms? What might be a good substitute for them? Thanks!!!5 stars

    1. Hi Kathleen! I’ve only tested the recipe as is but if you cut it in half then yes, it would likely fit into an 8×8 dish. You can leave the mushrooms out if you prefer. Zucchini might work for a substitution. If you decide to experiment, let me know how it goes!

    1. Hi Cynthia! I didn’t measure it out into cups when I made this. Just look for the smallest one you can find. Hope this helps!

  29. Hello!

    I hosted Friendsmas this past weekend and decided to have a veggie option (mainly) for one friend who is a vegetarian that was attending. It was a hit with everyone at the party (including myself!) and was near gone by the time it was over. I highly recommend this dish whether or not you are a vegetarian! It’s just a great change up from the typical bread-and-meat casseroles and is as delicious as any one of those! I will definitely make this again! Thank you so much!5 stars

  30. So good! We needed a vegetarian option for Christmas brunch and this was a huge hit. The sweet potatoes were a surprise ingredient that everyone loved. Thank you for a yummy new brunch staple!5 stars

  31. We absolutely loved this! We used feta. And we only had canned roasted red peppers on hand. The broccoli florets and quartered mushrooms made it more substantial. I called it our vegetable egg steaks! They were so delicious. We had the bake for dinner last night and now I am heating up the leftovers right now for breakfast! Thank you!5 stars

  32. This was a big hit at an annual breakfast gathering with friends. Leftovers were delicious as well. Definitely will make this again.5 stars

  33. Wow! Served this for family brunch as it was my turn to host. As I basically have stopped cooking over the years, I had no idea what I’d serve. I “googled” brunch make-ahead meals” and came across yours. Hmmm. Would I even be able to make this? How would it come out?
    WELL! Your step by step directions, shopping list, suggested alternatives were beyond helpful.
    I chopped the vegetables one day, prepared the egg mixture, topped with Feta cheeses and baked it the next day, warming and serving it the third day. PERFECT! Everyone had seconds with high accolades galore!
    I will freeze some squares for when my daughter visits, and will definitely make this again.

    Thank you for an easy to prepare yummy crowd-pleaser (even tho there were only four of us)5 stars

  34. Made this but traded in the ricotta for goat cheese. Delicious! Also roasted the vegetables the day before, so it came together quickly in the morning.5 stars

  35. I made this because my other breakfast casserole dish is laden with calories, fat and sodium. This was absolutely delicious!! Followed the recipe exactly but used more ricotta. It did require an additional 10 minutes in oven to firm up.5 stars

  36. This is great! It’s very forgiving as far as substituting what you have on hand but is perfect as written. Garlic in the custard mix is what really makes this recipe pop! I’ve added bread cubes, different cheeses, other veggies… it’s all good! Thanks for such a full proof recipe! ♥️5 stars

    1. Hi Jean! You’ll be using 12 eggs. Also you can find all of the ingredients and directions listed in the recipe card. It’s right above where you commented. You can use the “jump to recipe” button to help you get there faster!

  37. I’ve made this three times in one month for potluck brunch get together three different groups of friends and each time has gotten rave reviews and people want to take some home. Thanks for posting the recipe.5 stars

  38. This is absolutely delicious! I have made it as written and we have also added sausage and some shredded cheddar. Always delicious and everyone loves it.5 stars

  39. Fantastic! I changed up some veggies and seasoning based on what I had. I used potatoes, onion, red bell pepper and some veggie protein crumbles. We loved it! This goes on the regular rotation. Thank you for a great recipe!5 stars

  40. Made this today for a Christmas Eve breakfast/brunch. It was excellent! Everyone loved it and it’s so easy to make. I can’t wait to make it again. I love that it has so many vegetables. I made it exactly according to the recipe and wouldn’t change a thing. Thanks for a wonderful recipe!5 stars

  41. I work in a school and we have breakfasts for birthdays, showers and retirements. I’ve made your recipe three times and people rave about it! It is one of the best veggie egg dishes I’ve ever made. Thanks for the recipe!5 stars

  42. I plan to make this for a brunch with friends. It looks delicious and very healthy. One friend cannot eat onions and garlic and I’m wondering if you have any ideas of spices or something else to punch up the flavor a little bit. Cannot use onion powder or garlic powder either. Thank you.
    I’ve gotten some of my favorite recipes from you!

  43. I asked about substituting frozen vegetables but really only would substitute frozen broccoli and onions. Would this work?

    1. Hi! I worry those would get somewhat mushier and lack flavor vs roasted. If you do decide to try the shortcut (I see the appeal), definitely thaw them and pat them very dry first.

  44. This was really good and my family enjoyed it. It wasn’t wow, though so I think I’ll try feta cheese next time. Also Id add a bit more salt, like 1/4-1/2 to the eggs. I added an extra clove of garlic, but would try adding one more. I wonder about pan cooking the mushrooms and onions to pull out more flavor. I appreciated how healthy was and all the veggies!4 stars

  45. I made this for a Thanksgiving morning brunch we have and absolutely loved it! I used feta cheese as suggested in the write up but followed the recipe exactly. Now, I am having the leftovers for breakfast and think it is actually better today! Wow! I am definitely making this again and again!5 stars