The Day before Roasting:
Combine mustard, garlic, thyme, pepper and salt. Spread evenly over entire surface of prime rib. Wrap in plastic wrap and chill in Sub-Zero refrigerator overnight.
Two to 3 hours before roasting, remove prime rib from refrigerator and allow to sit at room temperature. Position oven rack to rack position 2. Preheat Wolf oven on CONVECTION ROAST at 500° F. Place prime rib on a roasting rack in large roasting pan. When oven is preheated, place in oven. Insert internal temperature probe in center of roast and set for 125°F. Roast for 30 minutes. Then reduce oven temperature to 300°F. Continue to cook 2 1/2 hours or until internal temperature has reached 125° F. Remove from oven and allow to “rest” for at least 20 minutes before carving.