Chef Elizabeth Karmel is the famed chef of New York City's favorite fried chicken and homemade pie joint, Hill Country Chicken, as well as of New York City and Washington, D.C.'s top Texas-style barbecue restaurant. Her favorite traditional holiday recipe is prime rib with horseradish cream and Yorkshire pudding. "It is always my family's traditional holiday dish — it's the star of our dinner, but very simple for a home cook to make! Make sure to order an untrimmed rib roast with the fat and rib bones still intact — this will baste the meat and keep it juicy during the long cooking time. I serve the prime rib with a decadent horseradish cream and a side of sizzling Yorkshire pudding."
Combine first 5 ingredients and grind in a spice grinder; set aside. Using a paring knife, cut a series of slits at least 2 inches apart into the roast. Insert garlic into half the holes and one sprig rosemary into the others. Coat the roast with a thin layer of olive oil first and then the spice rub. Place the roast (fat side up) in center of cooking grate on a bed of the remaining rosemary. Grill until done, 3½ - 4½ hours for medium-rare (11-13 minutes per pound), or until an instant-read thermometer reaches 130 degrees. Transfer the roast to a platter and cover loosely with foil. The meat will continue to cook and will gain 10 degrees to a perfect medium-rare temperature at 140 degrees. Let rest for 15-20 minutes before carving and serving.
While the roast rests, pour cream in a clean stainless steel bowl. Using an electric beater, whip on high until the cream forms soft peaks. Add 1-2 tablespoons of prepared horseradish — making sure it is not horseradish cream. Taste and adjust, adding more if you like it stronger. Season with sea salt and lemon zest. Serve immediately.