I got this recipe from my mother-in-law in New York and it is absolutely delicious and easy to make.
2 cans cream of chicken soup
16 oz sour cream
4-5 cooked chicken cubes or a quart of canned chicken
2 stacks ritz crackers
1 stick melted butter
Mix cream of chicken soup and sour cream together. Spread a thin layer of this into 9x13 pan. Spread cooked chicken over this. Pour the rest of chicken soup mix over the chicken. Crush ritz crackers and mix with butter. Spread this mixture on top. Cover with foil. Bake at 375 degrees for 25 minutes. Take foil off and cook for additional 5 minutes. This is great over rice.