Place onion and roast in a 5-qt. slow cooker. In a small bowl, combine the barbecue sauce, water, honey, garlic, seasoned salt and ginger; pour over meat. Cover and cook on high 5-6 hours or until meat is tender.
Remove meat; cool slightly. Shred meat with 2 forks and return to the slow cooker; heat through. Serve on buns. Cut sandwiches in half.
Freeze option: Place individual portions of cooled meat mixture in freezer containers. To use, partially thaw in refrigerator overnight. Microwave, covered, on high in a microwave-safe dish until heated through, gently stirring and adding a little water if necessary. Serve on buns.