Zucchini & Mushroom Casserole

1 pound zucchini, peeled and cubed
1 small onion, chopped
2 tbsp. butter
4 eggs, slightly beaten
2 c. cheddar cheese, grated
1/2 pound mushrooms, sliced
1 teaspoon dried basil
Salt and pepper
Preheat oven to 325 degrees. In a skillet, saute mushrooms and onion in butter until onion is soft.
Steam zucchini and mash it coarsely. In a medium-sized bowl, combine zucchini and eggs. Add mushrooms and onions. Pour into a greased casserole dish and bake, covered, for about 30 minutes, until eggs have set.