Spinach, potatoes, peppers, and onions mixed together with eggs form the base of this make-ahead feta breakfast casserole. A healthy breakfast casserole, perfect for any meal of the day and for meal prep.
Spray a glass pyrex baking dish with cooking spray.
Chop the onions, peppers, mushrooms, tomatoes, and spinach.
Heat 1 teaspoon olive oil in a pan over medium-high heat. Add the onions, peppers, and mushrooms and the frozen hash browns or O'Brien potatoes and saute until soft - about 6-7 minutes.
Mix together the eggs and milk in a large bowl. Add the tomatoes, chopped spinach, feta cheese, and the cooked veggies. Add salt and pepper to taste. Stir to combine.
Pour the mixture into the prepared baking dish. Bake for 45 minutes until the eggs have set and the top is slightly golden brown.
Serve with hot sauce and avocado or a dollop of sour cream