1/2 cup plus 2 tablespoons butter or margarine, divided
6 medium zucchini, thinly sliced
4 medium yellow squash, thinly sliced
1 8 ounce package sliced fresh mushrooms
1 onion, chopped
1 teaspoon salt
1 teaspoon ground black pepper
1 sleeve buttery round crackers, such as Ritz, crushed
1/2 cup grated Parmesan cheese
Preheat oven to 350 degrees.
Spoon squash mixture into a 13-x-9-x-2-inch baking dish; set aside.
In a medium saucepan over low heat, melt remaining 2 tablespoons butter. Remove from heat. Stir in crushed crackers and cheese. Sprinkle mixture over casserole.
Bake for 45 minutes.