Preheat oven to 375 degrees F. Heat the oil in a large skillet over medium-high heat. Season the chicken with salt and pepper, and then coat in flour, shaking off excess. Brown the chicken and then place in a casserole dish. Add the apples to the skillet and cook 1-2 minutes. Add remaining ingredients and bring to a simmer. Pour mixture over the chicken. Bake 30 minutes, basting occasionally, or until chicken is cooked. Divide chicken among plates, spoon over the sauce, and serve. Garnish with fresh rosemary sprigs, if desired.
Recipe Options: 4 Chicken legs could be used instead of the breasts, but the cooking time will be longer. For a less intense mustard taste, reduce the amount used. No rosemary? Try sage or thyme instead.