Prepare Chicken & Vegetables: Preheat your oven to 400°F (200°C). Pat the chicken thighs thoroughly dry with paper towels. In a large bowl, toss the sliced bell peppers and onions with 1 tbsp of olive oil, salt, and pepper. Set aside.
Season Chicken: In a separate bowl, drizzle the chicken thighs with the remaining 1 tbsp of olive oil. Season generously with smoked paprika, garlic powder, oregano, thyme, salt, and black pepper, ensuring all sides are coated.
Sear Chicken: Heat a large oven-safe skillet (cast iron recommended) over medium-high heat. Once hot, place the chicken thighs skin-side down and sear for 5-7 minutes until the skin is golden brown and crispy. Flip and sear for another 2-3 minutes.
Combine & Roast: Arrange the seared chicken thighs skin-side up in the skillet. Distribute the seasoned peppers and onions around the chicken. Transfer the skillet to the preheated oven and roast for 25-30 minutes, or until the chicken reaches an internal temperature of 165°F (74°C) and the vegetables are tender-crisp.
Rest & Serve: Remove the skillet from the oven. Let the dish rest for 5 minutes before serving. Garnish with fresh chopped parsley, if desired. Serve hot with your favorite side dishes.