Cook and bone chicken. Place chicken in bottom of 13 x 9 inch pan. Pour uncooked macaroni over chicken. Pour milk over macaroni. Spread soup over mixture. Cut cream cheese into small pieces and lay over soup. Cover and place in refrigerator overnight or at least 8 to 10 hours. One hour before baking, take out of refrigerator and let set. Heat oven to 350 degrees and bake for 50 minutes uncovered. Cover with onion rings and bake for 5 to 10 minutes more.