Spinach & Cheese Casserole

Ingredients
1 box frozen chopped spinach, cooked & drained well.
1 medium onion, cut into thin strips
2 cloves garlic, minced
2 Tbsp olive oil
1/2 -1 tsp basil
salt & pepper to taste
1 C sliced portabella mushrooms
1/2 C Shredded mozzarella cheese
1/3 C shredded Parmesan cheese
1/3 C crumbled feta cheese
3 eggs, beaten
bread crumbs (optional) & Parmesan cheese for topping

Directions
Preheat oven to 350°. Spray a shallow casserole dish with nonstick spray. Sauté onion & garlic in a little olive oil with salt, pepper, & basil until clear. Add mushrooms & saute until all is very soft. In a large heat-proof bowl, combine onion mixture with with cooked, well-drained spinach and the cheeses. Spread into prepared casserole dish. Pour beaten eggs evenly over mixture in casserole dish, sprinkle with bread crumbs & additional Parmesan cheese, & bake at 350° until lightly browned.