This recipe for prime rib uses the "closed oven method" to achieve a perfect medium-rare result every time. The meat is roasted at high heat for a short time, then slow roasted in a closed oven for 2 hours.
1. The night before cooking, unwrap the roast (save the weight tag) and let it sit uncovered in a dish or pan in the refrigerator; this will dry out the surface which will make it easier to get a nice brown color on the roast.
2. Three hours before cooking, take the roast out of the fridge and place it on a foil lined roasting pan with rack fat side up and let sit at room temp.
3. Half an hour before cooking, preheat the oven to 500°F; combine softened butter, pepper, garlic powder, rosemary and Italian seasoning in a bowl and mix until well blended; spread the butter mixture evenly over the entire roast and season the roast generously with kosher salt.
4. Place the roast in the oven and cook at 500°F for 5 minutes x the weight of the roast - i.e. for an 8 lb. roast you would cook for 40 minutes (8 lb. x 5 min = 40 min).
5. When the time is up, turn off the oven and leave the door closed. DO NOT open the oven door for any reason for the next 2 hours!
6. Prepare the horseradish cream by mixing the sour cream and horseradish and set aside; heat up the au jus 15 minutes before serving on the stove according to package instructions.
7. Take the roast out of the oven after 2 hours; internal temp should read 130°F - perfect medium rare! Carve and serve immediately.
Note: If you have an oven with an automatic fan that cools itself down, this method may not work for you.
