When ready to cook, heat an oven-safe (I used cast iron) skillet over medium heat. Slice green, red and yellow peppers. Add the remaining 2 tablespoons olive oil to the skillet and add peppers with a pinch of salt, reserving a few pepper slices. Stir and cook for 5 minutes. Push peppers to the side and turn heat up to medium high. Add chicken breasts and sear on each side until brown and crispy, about 5 minutes. After the second side has seared, top the chicken with the reserved pepper slices and add the entire skillet to the oven, uncovered. Bake for 25 minutes. Remove from the oven and immediately top with peanuts. Let sit for 5 minutes before serving.