Ingredients
Equipment
Method
- Season the rib roast thoroughly with kosher salt, making sure to include the rack of bones.
 - Rub the dry mustard all over the beef, then sprinkle with chopped fresh rosemary leaves and a generous amount of coarse ground black pepper.
 - Place the seasoned roast in a 12x14-inch roasting pan, cover loosely with plastic wrap, and let it rest in the refrigerator for 2-3 days to dry-brine.
 - Remove the rib roast from the refrigerator about 3 hours before cooking time to allow it to come to room temperature for more even cooking.
 - Position the oven rack in the lower third of the oven and preheat to 450°F.
 - Roast the prime rib rib-side up for 20-25 minutes until it starts to brown and sizzle.
 - Reduce the heat to 325°F and continue roasting until a meat thermometer reads 120°F when inserted into the thickest part, approximately 2 hours for medium-rare.
 - Transfer the roast to a carving board and let it rest for 25-30 minutes before slicing. The temperature will continue to rise during this resting period.
 - Remove and discard the chine bone that was tied back on.
 - Slice against the grain into thick portions and serve with the reserved pan juices spooned over the top.
 
Notes
For the best results, choose a well-marbled prime rib with bright red color, and if possible, one that has been dry-aged for extra flavor. Ask your butcher to remove the chine bone and tie it back on, which makes carving easier while still providing flavor during cooking.
The dry-brining process is essential for developing deep flavor, so don't skip the 2-3 day refrigeration period. If you're short on time, even 24 hours will make a difference.
Leftovers can be stored in an airtight container in the refrigerator for up to 4 days. They make excellent sandwiches with horseradish sauce or can be reheated gently at a low temperature to maintain juiciness.
