1 1/2 lb. yellow squash
1 sm. onion
1/2 stick butter
1/2 c. mayonnaise
1 c. cheddar cheese, grated
1 egg, beaten
Bread crumbs or onion rings

Cut up squash and onion. Steam in a little water until tender. Drain and mash (like potatoes). Add other ingredients and mix. Top with bread crumbs or onion rings. Bake at 325 degrees for 30 minutes.