Using the marinade above, coat the chicken pieces thoroughly and rub into the meat under the skin. Cover and refrigerate for 2 hours.
After chicken has marinated, remove and discard any remaining marinade in the container. Heat olive oil in a large skillet over medium-high heat. Sear the chicken on each side for 2-3 minutes, being careful not to burn. Transfer chicken to a 9” x 11” baking dish. In the same skillet, add pancetta and cook until crispy, about 4-5 minutes, stirring frequently to avoid burning. Add the onion, mushroom and celery and continue cooking until tender, about 3-4 minutes. Deglaze with the wine and reduce by half. Add the marinara, stock, sugar and crushed red pepper and bring to a boil.
When it comes to a boil, reduce the heat to low and return the seared chicken. Cover and cook until chicken reaches an internal temperature of 160, about 20-30 minutes. Allow to cool slightly before serving.