Cut the tempeh into chunks. Steam over boiling water for 15 minutes. Place the tempeh and sliced Onion in a deep dish and pour the barbecue sauce over it. Marinate in the refrigerator for at least one hour. Place on outdoor grill and cook until browned and heated through. Baste frequently with barbecue sauce. Can be cooked in a 350° F oven, covered for 30 minutes. Yield: 4 servings. Per serving: 435 calories; 20 grams protein; 12 grams fat (38%); 60 grams carbohydrate; 13 grams fat; 950 mg sodium.