Mustard-Crusted Boneless Prime Rib Roast with Cream Sauce

Ingeredients:

1 (6-pound) boneless prime rib roast, trimmed, tied
4 tablespoons store-bought or homemade Montreal-style steak seasoning, divided
1 cup sour cream
1/4 cup prepared horseradish
1 teaspoon freshly ground black pepper
1/2 teaspoon kosher salt
1/2 cup Dijon mustard, divided
1/4 cup (1/2 stick) melted unsalted butter

Instructions:

Season roast all over with 2 Tbsp. steak seasoning. Transfer to a wire rack set inside a rimmed baking sheet and let sit at room temperature 1 hour.
Preheat oven to 225ยฐF. Roast beef until an instant-read thermometer inserted into the center registers 120ยฐF, 3 1/2โ€“4 hours (start checking every 5โ€“10 minutes after 3 1/2 hours). Tent with foil and let sit at least 30 minutes and up to 1 hour. Increase oven temperature to 500ยฐF.
Meanwhile, whisk sour cream, horseradish, pepper, salt, and 1/4 cup mustard in a small bowl; set aside.
Remove string from roast; discard. Stir butter and remaining 1/4 cup mustard in another small bowl. Using a pastry brush, thickly coat roast with mustard-butter sauce. Coat with remaining 2 Tbsp. steak seasoning. Roast beef until a brown crust forms, 5-10 minutes. Transfer to a cutting board and carve. Serve with sour cream sauce alongside.
Sour cream sauce can be made 1 day ahead. Transfer to an airtight container and chill.

Recipe Card

Mustard-Crusted Boneless Prime Rib Roast with Cream Sauce

  • 1 6-pound boneless prime rib roast, trimmed, tied
  • 4 tablespoons store-bought or homemade Montreal-style steak seasoning (divided)
  • 1 cup sour cream
  • 1/4 cup prepared horseradish
  • 1 teaspoon freshly ground black pepper
  • 1/2 teaspoon kosher salt
  • 1/2 cup Dijon mustard (divided)
  • 1/4 cup 1/2 stick melted unsalted butter
  1. Season roast all over with 2 Tbsp. steak seasoning. Transfer to a wire rack set inside a rimmed baking sheet and let sit at room temperature 1 hour.
  2. Preheat oven to 225ยฐF. Roast beef until an instant-read thermometer inserted into the center registers 120ยฐF, 3 1/2โ€“4 hours (start checking every 5โ€“10 minutes after 3 1/2 hours). Tent with foil and let sit at least 30 minutes and up to 1 hour. Increase oven temperature to 500ยฐF.
  3. Meanwhile, whisk sour cream, horseradish, pepper, salt, and 1/4 cup mustard in a small bowl; set aside.
  4. Remove string from roast; discard. Stir butter and remaining 1/4 cup mustard in another small bowl. Using a pastry brush, thickly coat roast with mustard-butter sauce. Coat with remaining 2 Tbsp. steak seasoning. Roast beef until a brown crust forms, 5-10 minutes. Transfer to a cutting board and carve. Serve with sour cream sauce alongside.
  5. Sour cream sauce can be made 1 day ahead. Transfer to an airtight container and chill.
  • Low Carb Key Lime Cheesecake Fluff: The No-Bake, Creamy Dessert Youโ€™ll Make All Summer

    Low Carb Key Lime Cheesecake Fluff: The No-Bake, Creamy Dessert Youโ€™ll Make All Summer

    Some desserts feel like sunshine in a cup. This Low-Carb Key Lime Cheesecake Fluff is exactly thatโ€”a billowy, tangy-sweet cloud that tastes like the best slice of key lime pie, minus the crust and the carbs. Itโ€™s impossibly light, yet satisfyingly creamy, with that signature citrus zing that wakes up your taste buds. The best…


  • Keto Cheese Buns: The Low-Carb, Cheesy Bites That Make You Forget About Bread

    Keto Cheese Buns: The Low-Carb, Cheesy Bites That Make You Forget About Bread

    Thereโ€™s a quiet, golden moment in the kitchen when you pull a tray of warm, puffed buns from the ovenโ€”their tops glistening with melted cheddar and parmesan, their edges crisp and lacyโ€”and you realize youโ€™ve just baked something that tastes utterly indulgent yet fits perfectly into a low-carb lifestyle. These Keto Cheese Buns are that…


  • Irresistible Ham and Cheese Puff Pastry Squares: The Flaky, Golden Bites That Disappear in Minutes

    Irresistible Ham and Cheese Puff Pastry Squares: The Flaky, Golden Bites That Disappear in Minutes

    Some recipes live on stained, dog-eared notecards for a reason. Theyโ€™re the ones you bring to a party and leave with an empty platter and three requests for the recipe. Theyโ€™re the ones that feel fancy but are secretly easier than a grilled cheese. These Irresistible Ham and Cheese Puff Pastry Squares are exactly that…


Leave a Comment