1Chop up some fresh rosemary and thyme for the herb butter.
2In a mixing bowl, combine the chopped herbs, a stick of softened butter, garlic powder, onion powder, Tony's seasoning, salt, pepper, Dijon mustard, and Worcestershire sauce, then mix well.
3Pat the rib roast completely dry with paper towels.
4Using a paring knife, stab holes all over the rib roast.
5Thinly slice garlic cloves to create garlic slivers.
6Dip each garlic sliver in the prepared butter mixture to use as a lubricant.
7Sandwich each buttered garlic sliver with a small piece of rosemary and insert it into the holes in the rib roast, repeating the process.
8Spread the remaining herb butter mixture over the entire rib roast.
9Place the buttered rib roast on top of a roasting pan filled with celery, carrots, onion, a head of garlic, and any leftover herbs.
10Insert a thermometer into the thickest part of the meat.
11Roast the prime rib in the oven at 500 degrees Fahrenheit for about 15 minutes to achieve a nice color.
12Reduce the oven temperature to 325 degrees Fahrenheit and cook for approximately 13 minutes per pound, or until the internal temperature reaches 120 degrees Fahrenheit for a medium-rare finish.
13While the roast is in the oven, prepare the horseradish cream sauce by combining about a cup of sour cream, a few tablespoons of creamy horseradish sauce, a little Worcestershire sauce, black pepper, and chives in a container, then mix well.
14Set the horseradish cream sauce in the fridge to chill.
15Once the roast is out of the oven, tent it with foil and let it rest for at least 20 minutes; do not slice or remove the thermometer yet.
16For the au jus, strain all the drippings from the roasting pan into a measuring cup.
17Add 2 tablespoons of the fat from the drippings into a saucepan.
18Stir in a tablespoon of flour into the fat, cooking it out until the raw flour smell is gone (do not let it darken).
19Add 2 cups of beef broth and a cup of red wine to the saucepan.
20Add about a tablespoon of Worcestershire sauce to the au jus.
21Heat the au jus mixture until it's slightly thickened; it's not meant to be a gravy but should be thicker than water.
22Once the meat has rested, cut off the twine holding the bones.
23Remove the meat from the ribs.
24Slice the prime rib to your desired thickness.
25Serve the sliced prime rib with the au jus and horseradish cream sauce.
Make sure to take the rib roast out of the fridge to rest at room temperature for at least an hour before cooking.
Pat the rib roast completely dry, otherwise, the butter will be rejected.
Do not slice the meat immediately after removing it from the oven; let it rest to reabsorb all the juices and finish cooking to the perfect temperature.
The au jus is not meant to be a gravy, but a slightly thickened consistency is preferred over watery.
The horseradish cream sauce can be stored in the fridge while the meat rests.