Christmas Prime Rib

Gather all ingredients.

The day before you plan to serve the prime rib, remove roast from the package and dry thoroughly with paper towels. Set roast on a baking sheet, and place in refrigerator overnight. Remove from refrigerator 1 hour before cooking to allow beef to reach room temperature.

Rub prime rib roast all over with horseradish and Dijon mustard. Mix kosher salt, black pepper, thyme, and garlic powder together in small bowl; sprinkle over roast.

Preheat the oven to 450 degrees F (230 degrees C). Place celery, carrot, and onion into the bottom of a roasting pan; place roast on top.

Roast in the preheated oven for 30 minutes. Reduce oven temperature to 350 degrees F (175 degrees C), and roast until beef is browned and an instant-read meat thermometer inserted into the thickest part of the roast reads 130 degrees F (54 degrees C) for medium-rare.

Remove from oven, transfer roast to a platter, and cover with a tent of aluminum foil. Allow to rest for 30 minutes. The temperature of the beef will rise about 10 degrees during resting time.

To make au jus sauce: Skim excess fat from pan drippings in the roasting pan. Place the pan over medium heat and stir in beef base and 1 ½ cups of water. Bring to a boil while scraping and dissolving any browned bits from the bottom of the pan.

Strain out and discard vegetables. Combine cornstarch and 1 teaspoon of water in a small bowl until smooth; whisk into sauce.

Allow sauce to thicken slightly; pour into a gravy boat.

Serve and enjoy!