Coat the chicken pieces with the rub. Make sure the chicken has been pat dry before putting the rub. In a large skillet, sear the chicken for 4 minutes on each side. Remove from the heat and set aside.
Saute the other ingredients. In the SAME skillet, saute your red onion and garlic, and then add your mushrooms. Add the chicken back to your skillet with the garlic, onion and mushrooms.