Preheat the oven to 200F.
Season both sides of chicken thighs with salt and pepper. In a large skillet over medium-high heat add 1 tablespoon olive oil. When the oil is hot add 4 chicken thighs and half of bell peppers chunks. Cover with something heavy, like small heatproof lid and heavy cast iron lid on top, it will give this dish a beautiful sear that will caramelize the chicken thighs.
Cook for 5-7 minutes, or until brown sear.
Remove the lids, flip chicken thighs and bell peppers on the other side, sprinkle 1/2 tablespoon rosemary, cover with lids and cook for 3-5 minutes or until chicken thighs are cooked thru.
Transfer chicken thighs with bell peppers to a baking sheet, cover with foil paper and place it in the oven, to keep warm.
Repeat step 1-4 with the rest of the chicken thighs. Serve with mashed potato and salad. Grab a fork and enjoy!