1 tablespoon butter
8 ounces button mushrooms, sliced
1 small onion, sliced
10 ounces frozen spinach, thawed
4 eggs
1 cup milk
1 teaspoon garlic powder
salt and pepper
1/2 cup shredded mozzarella cheese
Preheat the oven to 350 degrees.
Melt the butter in a pan and add the sliced mushrooms and onions. Cook, stirring occasionally, until both ingredients are browned, about 10-12 minutes.
Place the cooked vegetables into a bowl and set aside to cool.
Wring out any excess liquid from the spinach. Chop it coarsely and set in the bowl with the mushrooms and onions.
Whisk together the eggs, milk, and garlic powder. Season the mixture with salt and pepper.
Spread the cooked vegetables into the bottom of a nonstick pie pan, and pour the egg mixture over the top. Sprinkle with the cheese.
Bake the crustless quiche for 45-50 minutes, or until just set in the middle. Cool for 15 minutes before slicing and serving.