4 chicken breasts, cooked
8 oz. cheese, grated
1 med. onion, chopped
1 can cream of chicken soup
8 oz. container sour cream
1 stick butter
1 pkg. Ritz crackers

Cut chicken into chunks. Layer casserole dish with chicken chunks. Next layer with chopped onions. Top with grated cheese. Mix together sour cream and soup; spread over layers in casserole. Melt stick of butter. Crumble Ritz crackers, add melted butter. Spread over mixture. Bake at 350 degrees for 30 to 40 minutes or until crackers are toasty brown.