Preheat your oven to 425°F (220°C).
Toss the halved baby potatoes with olive oil, salt, and pepper. Arrange them cut side down on a large, rimmed baking sheet. Transfer the baking sheet to the oven and roast for 20-25 minutes, or until golden and crispy. Remove from the oven but leave them on the baking sheet.
Season the chicken thighs with salt and pepper. Heat olive oil in a large, deep skillet or Dutch oven over medium-high heat. Sear the chicken thighs skin-side down until golden brown, about 5-6 minutes per side. Remove and set aside.
In the same pan, brown the sausage pieces until just cooked through. Remove and set aside.
Add the chopped onion to the pan, cooking until softened, about 3-4 minutes. Stir in the garlic and cook for 1 more minute until fragrant.
Pour in the white wine, scraping the bottom of the pan to release any browned bits. Let it simmer for 2-3 minutes until slightly reduced. Add the chicken broth, red wine vinegar, oregano, crushed red pepper flakes, pickled cherry peppers, brine, bell peppers , and rosemary or thyme. Stir well.
Transfer the seared chicken, browned sausage, and prepared sauce to the baking sheet with the roasted potatoes. Spread everything out evenly to ensure it cooks uniformly.
Return the baking sheet to the oven and roast for 20-25 minutes, or until the chicken is fully cooked (165°F internal temperature) and the sauce has slightly thickened.
Garnish with freshly chopped parsley and serve with crusty bread or pasta to soak up the delicious sauce. Add a squeeze of lemon for brightness, if desired.