Buying and trimming: When ordering the rib roast from a butcher, be sure to request a "top choice" roast cut from the small loin end; the best being ribs 12 through 10. Have the butcher cut off the chine/backbone. The rib bones look best if they are shortened and frenched, have the butcher do this for you as well.
- 1 (3-rib) prime rib beef roast, about 6 pounds
- 4 red onions, halved
- 4 carrots, cut in chunks
- 4 parsnips, cut in chunks
- 2 heads garlic, halved
Horseradish and Salt Crust:
- 1/2 cup prepared horseradish
- 5 garlic cloves, finely chopped
- 2 sprigs fresh rosemary, chopped
- 4 sprigs fresh thyme, chopped
- 1/2 cup kosher salt
- 2 tablespoons freshly ground black pepper
- 1/2 cup extra-virgin olive oil, plus more for drizzling
Preheat oven to 325 degrees F.
Put the onions, carrots, parsnips, and garlic into the bottom of a large roasting pan. Place the roast, rib side down, on top of the vegetables. In a small bowl mash together the horseradish, garlic, rosemary, thyme, salt, pepper, and olive oil to make a paste. Smear the paste generously over the entire roast and drizzle with some extra oil. Roast for about 1 1/2 to 2 hours or approximately 20 minutes per pound for medium-rare. Check the internal temperature of the roast in several places with an instant-read thermometer, it should register 125 degrees F. for medium rare. Remove the beef to a carving board, cover it with foil, and allow it to rest for 20 minutes. Note: the internal temperature of the meat will continue to rise about 10 degrees. Remove the vegetables and set aside. Pour the pan juices into a fat separator and set aside to allow the fat and beef juices to separate. Use the juices to serve with the meat and save the fat for Yorkshire pudding.