Preheat oven to 425ºF.
Mix together 1/2 cup of Dijon mustard, 1/4 cup of maple syrup (not pancake syrup), and 1 tablespoon of red wine vinegar.
Put chicken tenderloins or breasts in oven-proof baking dish. Season chicken with salt and pepper. Pour maple mustard mixture over them,
turning the chicken in the mixture so they are fully coated.
Bake in oven until a meat thermometer reads 165ºF. Approx. 25-30 for tenderloins. Baste the tops of the chicken with more sauce half way through baking. Let the chicken rest for 5 minutes before
serving. Spoon extra sauce over chicken, and sprinkle fresh rosemary on top.
Thaw chicken and sauce. Follow above instructions