01 - Preheat oven to 375°F. Position the rack in the center of the oven.
02 - Pat the chicken thighs dry with paper towels. Season generously on all sides with salt and freshly ground black pepper.
03 - In a large oven-proof skillet or Dutch oven, heat 2 tbsp olive oil over medium-high heat. Add the sausage pieces and cook until browned on all sides, about 4 minutes. Remove with a slotted spoon and set aside.
04 - In the same pan, place the chicken thighs skin-side down. Sear for 5 to 7 minutes per side until deeply golden. Remove the chicken and set aside with the sausage.
05 - Drain excess fat from the pan, leaving about 1 tbsp. Add the sliced onions, bell peppers, and minced garlic. Sauté until the vegetables soften, about 5 minutes.
06 - Stir in the halved cherry peppers and cook for an additional 2 minutes to release their briny heat.
07 - Pour in the dry white wine, scraping up any browned bits from the bottom of the pan. Let the wine reduce by half, about 3 minutes.
08 - Add the chicken broth, red wine vinegar, dried oregano, and fresh rosemary. Return the sausage and chicken to the pan, arranging the chicken skin-side up.
09 - Bring the mixture to a simmer on the stovetop, then transfer the uncovered skillet to the oven. Bake for 30 minutes until the chicken is cooked through and the sauce has thickened.
10 - Remove from the oven and let rest briefly. Garnish with freshly chopped parsley before serving.