- Preheat oven to 400ºF and lightly grease a large cast iron skillet or Dutch oven with cooking oil. Arrange chicken thighs in skillet and season with salt and pepper.
- Whisk together chicken stock, orange sauce, mustard, rosemary and garlic.
- Pour sauce evenly over chicken thighs. Bake uncovered for 30-35 minutes, basting chicken thighs with sauce every 15 minutes. Turn oven to broil and broil for 5 minutes longer.
- Serve hot garnished with extra rosemary.