Squash Casserole

Squash Casserole 7 or 8 yellow squash, medium sized
1/2 large onion
salt and pepper
1 egg
1/2 cup mayonnaise
4 ozs. shredded cheddar cheese, divided
1 roll buttery crackers
Slice squash and place with onion in covered pan.  Steam over low heat  ( I don't add water but let the natural water content do the steaming) until vegetables are tender.  Pour into colander to drain.  Salt and pepper to taste.  Now add 1 egg, 1/2 cup mayonnaise and 3 ozs. shredded cheddar cheese.  Mix well and top with 1 ounce shredded cheddar.  Top with 1 roll crushed butter flavored crackers.  Bake at 350F for 30 minutes until top is golden.  May be frozen unbaked or baked.