Bring 1 1/2 cups of water to a boil. Add 1/2 teaspoon kosher salt and the quinoa. Return to boil, cover, then reduce heat and simmer for 12 minutes, until most of the liquid is absorbed. Remove from the heat, fluff with a fork, then recover and let stand for 15 minutes. (This is the cooking process for the brand of quinoa I use. Check the package of your quinoa and cook according to its directions.) Set cooked quinoa aside.
Place a rack in the upper and lower thirds of your oven and preheat your oven to 400 degrees F. While the quinoa cooks and the oven preheats, place the tofu between two kitchen towels and set it on a plate. Place a second plate on top, then press firmly to press out as much water from the tofu as you can, changing out the towels as needed. Dice into 3/4-inch cubes, then spread in a single layer on a baking sheet lined with parchment paper.
Place the broccoli, cauliflower, and onion on a second baking sheet and drizzle with olive oil. Sprinkle with 1/2 teaspoon salt and black pepper, toss to coat, then spread into an even layer. Place both baking sheets into your oven. Bake the tofu until dry and firm, about 20 minutes, and the vegetables until caramelized and tender, about 25 minutes. Flip the vegetables once halfway through, and rotate the top and bottom rack positions of the baking sheets. Set aside.
While the vegetables and tofu cook, prepare the dressing: In the bowl of a food processor or blender, place all of the dressing ingredients—tahini, lemon juice, mint, parsley, salt, and pepper, and add 1/2 cup water. Blend until smooth.
Once the tofu is cooked, let cool slightly, and then place the tofu cubes in a bowl with 1/4 cup of the dressing and toss gently to coat. To assemble the bowls, scoop quinoa into a bowl, then top with the roasted vegetables, dressed tofu, and avocado, along with cucumber, almonds, and additional fresh mint and/or parsley as desired. Serve remaining dressing on the side and use as a dip or spoon over the top as desired.
Notes
TO STORE: I recommend saving the different components of the Buddha bowl (tofu, veggies, quinoa, and dressing) separately, then combining and reheating just before serving. Saved in this way, the veggies can keep for several days in the refrigerator and the tofu for 1 week. The dressing will last in an airtight jar in the refrigerator for 2 weeks.
TO REHEAT: Assemble the buddha bowls as directed with the leftover tofu, dressing, quinoa, and roasted veggies. Warm until heated through in the microwave and then garnish as desired with additional toppings.
TAHINI SUBSTITUTE: I haven't tried it, but I suspect natural creamy almond, cashew, or peanut butter would be a delicious substitute for the tahini. Because nut butter is thicker than tahini, you may need to thin the dressing with additional water to reach a sauce-like consistency.
VEGETABLE SWAPS: Not a fan (or out of) broccoli and cauliflower? Try this recipe with roasted sweet potatoes, zucchini, or any of your other favorite veggies!