Poor Mans Prime Rib

Put the roast in the oven when it’s ready to cook. Turn down the heat to 475 °F, or 245 °C. Allow the roast to rest in the preheated oven for two and a half hours after roasting for 21 minutes (or seven minutes per pound). At this very moment, you must not open the door.
Roasts should be taken out of the oven when their internal temperatures reach 145 degrees Fahrenheit (65 degrees Celsius). Before serving, thinly slice the meat.