1 pkg. frozen broccoli or squash
1/2 c. mayonnaise
1 egg
1 sm. onion, chopped and sauteed
3/4 c. each Cheddar and Mozzarella cheese

Butter a round casserole dish. Mix all ingredients and place in casserole dish. Cover and microwave on high for 12 minutes. Top with crushed Ritz crackers. Pour butter over crackers and brown in oven.