1Blend spices together. Set aside. Remove insides from chicken and wash thoroughly. Rub chicken(s) inside and out with the spice rub, also some under the skin. Put onion inside cavity of chicken(s). Put chicken in a large zip lock bag and marinate several hours or overnight. When ready to cook, preheat oven to 250 degrees. Place chicken(s) in large roasting pan and cook 5 hours (yes that's right, 5 hours - don't worry, it's safe at that temperature). After the 1st hour, spoon some of the drippings over chicken about every 30-45 minutes. After cooking, let chicken rest for about 10 minutes before carving.