This copycat Texas Roadhouse prime rib is utterly delicious! Slow-roasted with a garlicky, peppery rub, serve this with all the sides, a homemade au jus, and creamy horseradish sauce.
Pat 1 (6-pound) rib roast completely dry with paper towels.
In small bowl, mix 2 tablespoons kosher salt, 1 tablespoon coarsely ground black pepper, 2 teaspoons garlic powder, 2 teaspoons onion powder, 1 teaspoon smoked paprika, 1 teaspoon dried thyme, 1 teaspoon crushed dried rosemary, and ½ teaspoon cayenne pepper.
Rub 2 tablespoons olive oil over entire roast, then coat every surface generously with seasoning.
Place roast fat side up on rack in roasting pan. Refrigerate uncovered overnight, 12-24 hours.
Roast Prime Rib
Remove roast from refrigerator 2 hours before cooking to come to room temperature. Preheat oven to 250°F.
Roast uncovered on rack until thermometer inserted in center reads 120°F for medium-rare or 130°F for medium, about 3 to 3½ hours. Begin checking temperature after 2 hours.
Transfer roast to cutting board, tent loosely with foil, and let rest 30 minutes.
Make Horseradish Sauce
While roast rests, stir together ½ cup sour cream, 2 tablespoons mayonnaise, 2 tablespoons prepared horseradish, 1 teaspoon Dijon mustard, 1 teaspoon fresh lemon juice, ¼ teaspoon kosher salt, and pinch black pepper in medium bowl.
Taste and add up to 1 more tablespoon horseradish for sharper sauce. Cover and refrigerate until serving.
Make Au Jus
Pour drippings from roasting pan into fat separator or glass measuring cup and skim off most of fat.
Melt 1 tablespoon butter in medium saucepan over medium heat. Add minced shallot and cook 2 minutes.
Add 2 minced garlic cloves and cook 30 seconds.
Add 2 cups low-sodium beef broth, 1 tablespoon Worcestershire sauce, 1 sprig fresh thyme, and skimmed drippings. Simmer 10 to 12 minutes, until reduced by about one-third.
Remove thyme sprig. Off heat, whisk in 1 tablespoon cold butter until glossy. Season with kosher salt to taste.
Sear and Serve
Increase oven to 500°F. Wipe out roasting pan to remove any remaining fat, then return rested roast to rack in pan.
Roast 5-8 minutes, until deeply browned and crackling. Watch closely so crust doesn’t burn.
For bone-in roast, cut along bones to remove them. Slice roast into ¾ to 1-inch-thick slices.
Serve immediately with warm au jus, horseradish sauce, baked potatoes, and salad, garnished with fresh thyme or rosemary sprigs.
Recipe Notes
Plan ahead: Dry brine roast in the fridge overnight, then let sit at room temperature for 2 hours before roasting. Neither step is included in total recipe time.Salt: If using Morton instead of Diamond Crystal, use 1 tablespoon plus 1 teaspoon.Doneness: Pull it at 120°F for medium-rare or 130°F for medium. Start checking after 2 hours. The roast will climb 5-10 degrees during the rest period and final sear.Boneless roast: If you cook a boneless roast, it cooks 20-30 minutes faster. Start checking after 1½ hours.