In a large skillet or Dutch oven, heat the olive oil over medium-high heat. Season the chicken thighs with salt and pepper, then add them to the skillet, skin-side down. Brown the chicken for about 5-7 minutes on each side until golden. Remove the chicken and set aside.
In the same skillet, add the Italian sausage pieces and cook until browned, about 5 minutes. Remove the sausage and set aside with the chicken.
Add the diced onion to the skillet and sauté for about 3-4 minutes until softened. Stir in the minced garlic and red pepper flakes, cooking for another minute until fragrant.
Pour in the white wine, scraping the bottom of the skillet to deglaze. Allow it to simmer for 2-3 minutes until slightly reduced.
Add the chicken broth, apple cider vinegar, rosemary, thyme, and the browned chicken and sausage back into the skillet. Bring to a simmer.
Cover the skillet and reduce the heat to low. Let it cook for about 30-35 minutes, or until the chicken is cooked through and tender.
Uncover and cook for an additional 5-10 minutes to thicken the sauce slightly. Taste and adjust seasoning with salt and pepper if needed.
Serve hot, garnished with fresh parsley and lemon wedges on the side.