This low-carb breakfast is excellent on its own but it can also be added to a piece of whole grain toast for a heartier meal. Eggs are an awesome protein and adding spinach to your morning meal is a great way to get in all the servings of veggies you need.
Preheat to 375°F.2.
Spray a sheet pan (10-inch by 5-inch) with cooking spray. Arrange mushrooms evenly on the pan and drizzle with 1 tablespoon of the olive oil. Bake for 10 minutes.3.
While mushrooms are baking, sauté onion in oil for 1 minute. Add spinach and cook 1 minute more, until lightly wilted; set aside.4.
Whisk the eggs, milk, cheese, salt and pepper together in a bowl. Add the spinach and onion to the egg mixture. Remove sheet pan from oven, pour egg mixture into the pan; then carefully transfer it to the oven and bake 17 to 18 minutes, until just set and golden around edges.5.
Cool for 5 minutes, then cut into 12 square servings. Leftovers can be stored in an airtight container for up to two days.