Rinse chicken, pat dry with paper towels. Place onion inside chicken, truss for roasting or secure on spit. Preheat oven to 325 degrees or prepare for rotisserie. Combine remaining ingredients. Brush chicken with mixture. Roast about 2 1/2 to 3 hours, until done on grill or rotisserie, basting frequently with butter-herb mixture. Makes 4 to 6 servings.