Preheat oven to 425.

In a mixing bowl, combine the vinegar, honey, whole grain mustard, Dijon mustard, garlic, and cayenne pepper. Split the mixture in half. Add the chicken breast to one half of the liquid and marinate for 30 minutes.

After the chicken has marinated, heat 1 tablespoon of the olive oil in a large oven safe skillet. Remove the chicken form the marinated (discard remaining marinade from the chicken) and add the chicken to the hot oil and sear on each side.

Meanwhile, toss the potatoes with the remaining oil and rosemary. Add to the large skillet with the seared chicken, drizzle the reserved half of the balsamic vinegar mixture over top, and remove the skillet form the heat and place in the oven. Cook for 10 minutes. Remove the pan from the oven, stir, and cook for 10 more minutes or until potatoes are tender.