Combine sage and rosemary. With fingers, carefully loosen skin from the turkey breast; rub herbs under the skin. Secure skin to underside of breast with toothpicks.
Place breast side up on a rack in a roasting pan. Stuff turkey with apple, onion and celery. Brush with butter.
Bake, uncovered, at 325° for 3 to 3-1/2 hours or until a meat thermometer reads 180°, basting occasionally with pan drippings. (Cover loosely with foil if turkey browns too quickly.) Brush with apple jelly. Cover and let stand for 15 minutes before removing toothpicks and carving. Yield: 14 servings.