A beautiful prime rib roast is usually a special-occasion centerpiece, one that’s surrounded by equally special side dishes. All that makes for a busy day in the kitchen, and when you add in the worry of an overcooked roast, it can be overwhelming.
We’re here to calm your nerves. Our method allows you to do the prep work, start the roast, and then leave it alone and, more important, not worry about it overcooking while you attend to the rest of the meal. The key? Some simple — and we mean simple! — math.
The method involves starting the roast in a hot oven for a predetermined amount of time based on its weight, and then shutting off the oven and letting the roast climb slowly to medium-rare over the course of the next two hours in the oven’s residual heat. With a little elementary math, this method works for any size roast. And since it’s seared in the oven rather than on the stovetop, the process is far less messy.
We tinkered with this equation and ended up with three minutes of “on” time per pound for a boneless roast. So, for a 3 1/2-pound roast this walk-away method requires 11 minutes at 500 degrees before turning off the oven completely and leaving it alone for two hours.
After a 20-minute rest out of the oven, the roast yielded perfectly juicy, medium-rare slices. What’s more, I had two hands-free, worry-free hours to prepare side dishes to go with it. Happy holidays, indeed.
Easier Prime Rib
1 1/2 tablespoons kosher salt
1 1/2 tablespoons pepper
1 (3- to 3 1/2-pound) boneless prime rib roast
2 tablespoons Dijon mustard
- Adjust the oven rack to the middle position and heat the oven to 500 degrees. Line a rimmed baking sheet with aluminum foil and set a wire rack in the sheet; spray the rack with vegetable oil spray. Combine salt and pepper in bowl.
- Using a scale, weigh the prime rib. Round the weight up to nearest 1/2 pound. Multiply the rounded weight by three, then round that number up to the nearest whole number. Record that number; this will be your oven-on roasting time.
- Pat the prime rib dry with paper towels. Brush all over with mustard. Sprinkle salt and pepper mixture evenly on all sides. Transfer to the prepared wire rack, fat side up.
- Transfer the sheet with the prime rib to the oven and roast for the time recorded in Step 2. Without opening the oven door, turn off the oven and leave roast in the oven, undisturbed, for two hours. Do not open the oven during this time.
- Remove the sheet from the oven and let the prime rib rest on rack for 20 minutes. Transfer the prime rib to a carving board. Slice 1/4 to 1/2 inch thick. Serve with horseradish.
- You can substitute other complementary spices for the pepper, if desired.
- It’s good to use an oven thermometer to ensure that your oven truly reaches 500 degrees before starting.
- It is critical that you not open the oven door at all while the roast is cooking. If you do, the heat will escape from the oven and the calculated cooking time will be ineffective.