Trim any excess fat from chicken pieces; remove skin from legs and breast.
Spread onion in bottom of a 12 cup baking dish; arrange chicken in 2 layers on top.
Stir Worcestershire sauce into soup in can; spoon over chicken; cover.
Bake in moderate oven (350Â°) 1 hour; uncover and stir to mix soup and chicken juices; cover again.
Bake 1 hour longer, or until chicken is very tender.
Let casserole stand about 1 minute, or until fat rises to the top; skim.
Serve chicken with hot noodles, gravy.