Combine steak sauce, bouillon cubes, salt, pepper, sugar and hot water in crockpot; stir well. Add remaining ingredients except flour; mix carefully.
Cover and cook on Low setting for 7 to 10 hours or on high setting for 4 hours. Before serving, remove chicken and bone, and return meat to crockpot; stir well.
To thicken gravy, make a smooth paste of flour and quarter cup of juices from stew. Add to crockpot. Cover and cook on High setting until thickened.