you cook a prime rib roast at 500 degrees for 5-6 minutes per pound, then turn the oven off and leave the door closed for two hours. At that point, the temperature of the prime rib will be perfect ...

If you don’t let the meat rest long enough, you could end up with a chewy prime rib roast,” warns Petropoulos. “As the roast rests, the internal temperature will rise 5 - 10 degrees.