HEAT oven to 350°F.
PLACE meat, fat-side up, on rack in pan; top with garlic and onion.
BAKE 1 hour. Pour barbecue sauce over meat; cover.
REDUCE oven temperature to 300°F. Bake 2 hours or until meat is tender and done (160°F). Skim fat from liquid in pan; discard. Serve liquid with meat.