Remove core from whole head of cabbage with sharp knife. Scald cabbage in boiling water. Remove a few leaves at a time, as they will wilt. Cool before using. Saute onion in butter until transparent. Combine with meat, egg, rice and seasonings and mix well. Spread each leaf with meat, about 1/2 inch thick. Fold the two opposite sides and roll, starting with one of the open ends. Fasten with toothpicks.
Place cabbage rolls in baking dish, cover with bacon and roast uncovered for 2 hours at 300 degrees. Baste from time to time with juice and drippings.