Preheat oven to 200 degrees.
Season chicken with salt and pepper.
Heat 12 inch skillet over medium high heat, add 1 tablespoon oil.
Place 4 thighs and eight pepper pieces.
Cover chicken with a smaller heavy pan (to weigh down chicken and peppers).
Cook 5 to 7 minutes.
Remove weight, turn chicken and peppers over.
Sprinkle half of the rosemary over chicken.
Reduce heat to medium.
Return weight back on top of the chicken in the skillet.
Continue cooking until thighs reach 165 to 170 degrees.
Remove thighs to baking sheet and cover, then put in oven.
Repeat with remaining chicken, oil, and peppers.