In a large skillet with a tight-fitting lid, heat the olive oil over medium-high heat. Once the oil is hot and shimmering, add the florets, salt, and black pepper. Shake the skillet so that the florets are in an even layer. Let cook undisturbed for 3 minutes. The broccoli should crisp in places on the first side.
Stir in the garlic and red pepper flakes. Cooking, stirring constantly, until the garlic is very fragrant, about 30 seconds.
Reduce the heat to medium, add the water, and cover the pan. Continue cooking, covered, until the broccoli is fork tender and a vibrant green color, about 2 to 4 minutes, stirring every minute or so, and ensuring that the broccoli does not burn.
Stir in the lemon zest and sprinkle with Parmesan. Season with more salt, black pepper, and red pepper flakes to taste. Enjoy warm.
Notes
TO STORE: Refrigerate sautéed broccoli in an airtight storage container for up to 5 days.
TO REHEAT: Heat leftovers in a skillet set over medium heat or in the microwave.
TO FREEZE: Freeze the broccoli in an airtight container or freezer bag for up to 3 months, then thaw in the refrigerator before heating.