Preheat oven to 350 degrees.
Grease a casserole (I use a 9″ x 13″) with butter or olive oil.
Beat eggs in a bowl and add spinach, tomatoes and cooked vegetables.
Bake for about 45 minutes or until the top is lightly browned.
Sprinkle with shredded full-fat cheese, salt, pepper and/or flax seed, if desired.
Cut into six squares and either serve your family their meal or portion and refrigerate or freeze for quick, healthy breakfasts or snacks.