1Heat gas or charcoal grill. In small bowl, mix hoisin sauce, soy sauce, vinegar, garlic and gingerroot; set aside.
2Place hot dogs on grill over medium heat. Cook uncovered about 10 minutes, turning frequently, until hot.
3Spread desired amount of barbecue sauce on cut sides of each bun. Place grilled hot dogs in buns; top with onions. Refrigerate any remaining sauce up to 1 week.