Prime Rib - cooking recipe

Ingredients

1 (10 -12 lb) five bone standing rib roast, chine bone removed and tied back on (10-12 lbs.)
2 tablespoons kosher salt
1 1/2 tablespoons dry mustard, preferably Coleman's
1 1/2 tablespoons chopped fresh rosemary leaves
fresh coarse ground black pepper, to taste

Preparation

Season beef with salt, including the rack of bones. Rub mustard all over beef; sprinkle with rosemary and pepper. Set beef in a 12x14-inch roasting pan. Cover loosely with plastic wrap and refrigerate for 2-3 days.
Remove beef from refrigerator 3 hours before you are ready to roast it, to allow it to come to room temperature.
Arrange rack in lower third of over and heat to 450\u00b0F.
Roast the beef, rib side up, until it begins to brown and sizzle, 20-25 minutes. Reduce heat to 325\u00b0F; continue roasting until a meat thermometer inserted in the thickest part of the meat registers 120\u00b0F for medium rare, about 2 hours.
Transfer roast to a carving board and let rest for 25-30 minutes. Remove and discard chine bone. Carve roast and serve with reserved pan juices.