Remove giblets and neck from turkey; reserve for gravy. Rinse turkey with cold running water; drain well. Blot dry with paper towels. Sprinkle salt and pepper into cavities of bird.
Fold neck skin and fasten to the back with skewers. Fold the wings under the back of the turkey. Return legs to the tucked position.
Place turkey, breast side up, on a rack in a large shallow (no more than 2 ½” deep) roasting pan. Insert an oven-safe thermometer into thickest part of the thigh, being careful it does not touch the bone. Roast turkey in a preheated 325 degree F oven for about 3 ¾ hours.Baste with the pan juices.
Meanwhile, in a small bowl, blend honey and mustard together. During the last 30 minutes of roasting time, baste the bird with the honey glaze. Continue to roast until the thermometer registers 180 degrees F in the thigh, or 170 degrees F in the breast.
Remove the turkey from the oven and allow the bird to rest for 15-20 minutes before carving. Place on a warm, large platter and garnish with grapes.
