Remove your prime rib from the refrigerator one hour before cooking. Season it on all sides with salt and cover it loosely with plastic wrap as it comes to room temperature. Prime rib roast will cook better and more evenly when it’s at room temperature.
When you are ready to cook the prime rib, lower/adjust your oven rack so the meat will cook in the center of the oven. Preheat the oven to 500 degrees F.
In the meantime, mix together 1 1/2 teaspoons salt, pepper, rosemary, thyme, garlic, and olive oil.
Pat the roast with paper towels. Spoon seasoning over it, rubbing it onto all sides. Place bone-in roast with the bones down, inside a roasting pan cast iron pan. Place a boneless roast on a rack inside the pan.
Bake prime rib at 500 degrees for 15 minutes, then reduce the oven temperature to 325 degrees and continue baking until desired doneness: Rare: cook until thermometer reaches 120 degrees F (about 10-12 min/pound)Medium rare: Cook until thermometer reaches 130 degrees F (about 13-14 min/pound)Medium: Cook until thermometer reaches 140 degrees F (about 14-15 min/pound)Medium well – Cook until thermometer reaches 150 degrees F A couple of things to keep in mind:
- A meat thermometer is essential to ensure it cooks to your perfect doneness. Not all roasts or ovens are the same!
- Also, the meat will continue to cook once it’s taken out of the oven (your thermometer will continue to rise 5-10 degrees) so remove it from the oven 5-10 degrees before it reaches your optimal temperature.
- Remove it from the oven and tent it with foil. Allow it to rest for 30 minutes before carving.