How to Cook a Rib Roast

The night before you are going to cook the prime rib, unwrap the roast and let it sit uncovered in the refrigerator. This will dry out the surface, allowing for an even, crisp crust. Three hours before you want to begin cooking, take the roast out of the fridge and place it on a sheet pan at room temperature. Half an hour before you start roasting, preheat your oven to 500°F and season the roast generously with Kosher salt and freshly ground black pepper. Now it’s time to do your calculation; simply multiply the weight of your roast by five. That’s your total roasting time, in minutes. For instance, if you have a four-pound roast, 4 × 5 = 20 minutes. An eight-pound roast? 8 × 5 = 40 minutes. Remember that number. When you’re ready to cook, set the roast in a roasting pan with a rack, fat-side-up. If you’re nervous about this crazy technique, you can insert a meat thermometer or a digital-probe thermometer into the deepest part of the meat, being careful not to hit bone. If nothing else, it will provide you with some peace of mind. All right, now put the roast in the oven and roast it for exactly however many minutes you calculated above. When the time’s up, turn off the oven and walk away. Don’t open the oven door for any reason for the next 2 hours. Do not open the oven door, for any reason, for the next 2 hours. In 2 hours, take the prime rib out of the oven, and let rest. If you did use a thermometer, you’ll see that the internal temperature of the meat has reached 130°F—in other words, perfect medium-rare.