1. Add all seasonings to a glass bowl. Using a fork, combine seasonings with harissa paste to form a wet-dry rub.
2. Thoroughly coat your chicken with the rub. Be sure to coat the meat of the chicken as well as the skin. Cover with plastic wrap or foil, and marinate in the refrigerator for at least 2 hours. For best results, prepare the night before.
3. Heat 1 tablespoon of olive oil and 1 tablespoon of butter in a cast iron skillet over medium to high heat. When the oil is hot, sear each piece of chicken 2 minutes on each side. For a proper sear, do not overcrowd the skillet.
4. When finished, add all the chicken into the skillet. Add 1 tablespoon butter on top of chicken and bake in the oven for 45 minutes, or until the chicken reaches an internal temperature of 165 degrees F. Allow the chicken to rest 10 minutes before serving.
5. For a delicious optional treat, sauté some red onions and mushrooms in the skillet with the juices left over from the chicken.