Place the sausage in a shallow roasting pan a bake at 350 degrees for approximately 45 minutes, when cooked, slice on the bias 1" thick pieces and set aside.

Slice each breast into thirds on the bias. Pat chicken dry and season with salt and pepper. Heat 1 tablespoon oil in a 12-inch heavy skillet over moderately high heat until hot but not smoking, then sauté chicken in 2 batches, beginning skin sides down, turning occasionally and adjusting heat to keep from burning, until cooked through and well browned on all sides, 10 to 12 minutes (add another tablespoon oil to skillet for second batch).

Transfer chicken as cooked with tongs to a plate and keep warm, covered with foil.

Pour off all but 1 tablespoon fat from skillet. Add remaining tablespoon oil and cook onion, bell peppers, and pepperroncini  peppers (to taste) over moderate heat, covered, stirring occasionally, until softened, about 7 minutes.

Add garlic and cook, stirring, until garlic is golden, about 2 minutes. Add wine and broth and boil, uncovered, until most of liquid is evaporated, about 4 minutes.

Add sausage and chicken (with any juices accumulated on plate) and parsley and cook over moderate heat, stirring, until heated through, then season with salt.