This technique produces a perfectly medium-rare prime rib with a gorgeous brown crust on the outside. It works best for smaller prime ribs of between 4 and 8 pounds. For a bone-in prime rib, figure two servings per rib, while a boneless roast will yield two servings per pound.
The key to this method is knowing the exact weight of your prime rib. Just copy it off the label, write it on a Post-it and stick it on your fridge. I say this because I know how easy it is to just tear off the butcher paper and throw it away, and you really don’t want to have to go digging through the trash to find the label.
Also, you don’t actually need a meat thermometer with this technique (although if you’re paranoid you can certainly use one anyway).
You’ll also notice that there’s no resting time with this recipe, which might come as a surprise if you’re used to resting your meat after roasting it. And if you’re used to doing that, that’s good. But with this recipe it’s not necessary because the meat is basically resting as it sits in the oven.
- 1 boneless or bone-in beef rib roast (trimmed and tied)
- Kosher salt (to taste)
- Freshly ground black pepper (to taste)
Steps to Make It
Gather the ingredients.
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, which makes it easier to get a nice brown color on the roast.
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, pre-heat 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. All you do is multiply the weight of your roast by five. That’s your total roasting time, in minutes. Sounds crazy, right? But stay with me. 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 two hours. I’ll say it again because it bears repeating: Do not open the oven door, for any reason, for the next two hours. When the roast is done, here’s a simple au jus sauce you can make with the pan juices. Or try this creamy horseradish sauce.
In two hours, take the prime rib out of the oven, carve and serve right away. 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. How easy was that?