Prime Rib with Roasted Garlic and Horseradish Cream Sauce

Prime Rib with Roasted Garlic and Horseradish Cream Sauce on a platter with serving fork
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Seasoned home cook, or novice alike this easy prime rib with roasted garlic will have all your friends and family singing your praises!

Prime Rib Roast, We’ve Never, Ever Tasted Anything So Good. 

A perfectly-cooked slab of juicy prime rib, slathered with creamy, lightly-spicy horseradish sauce and speared with a sweet-savory clove of roasted garlic?! Forgive the hyperbole, but make this prime rib for yourself and get back to us—we think you’ll be waxing pretty poetic yourselves. We’ll walk you through a few simple tricks and tips for making sure you pull a show-stopping prime rib out of the oven every time.

Rich, juicy, savory and oh-so-decadent, our prime rib roast recipe just screams celebration. Prime rib is a classic for a reason—a little extravagant, a lot delicious, it is possibly the ultimate way to treat your dinner guests like royalty. And—especially if you have a meat thermometer handy—it is also, conveniently, quite easy to master.  

Uncooked Prime Rib tied up in a roasting pan

Prime Rib 101: What Cut of Meat is a Prime Rib?

This is a really common question, and a great one, too! There’s no way around it, prime rib is a splurge. Go to a local butcher that you trust, and let them help you kick things off on the right foot with a great cut of meat. Here’s what to ask for:

  • A three bone rib roast is what we call for in our prime rib recipe. But if you’re serving more than six people, a good rule of thumb is that one rib serves two people.
  • Ask them to de-bone the prime rib, if you’d like to do a little less work when it’s time to carve your prime rib roast. Or, leave it bone-in for a more dramatic presentation.
  • Have your butcher truss the prime rib roast for you. You’re spending a decent amount of money, it’s the least they can do!

This is the Best Prime Rib Recipe in the World Because:

  • We dry-brine the meat! In exchange for a just a little bit of planning ahead, you get a super moist, flavorful prime rib roast—trust us, it’s worth it.
  • It takes almost no time to make. Seriously. Rub a few spices on it, and leave it alone in a hot oven while you go do something else. What more could we wish for?
  • Slices of this prime rib make very good roasted garlic and horseradish cream sauce delivery vehicles. It’s just not a party until we’re slathering something in rich, savory, lightly spicy cream sauce—and a rib roast is prime (cue eye roll) for slathering.
  • Did we mention roasted garlic? We could have just stopped with the prime rib and horseradish sauce, but we think that if you’re going over the top—and if you’re serving prime rib, you’re going over the top—why not go just a bit further and roast some garlic. It roasts alongside the prime rib, turning sweet and spreadable with almost no effort—a little extra oomph.
  • It makes everyone around your table feel really, really special. Prime rib is a little expensive, and it takes a little time—it’s just not an everyday thing, and people know that. It’s a great, simple way to go the extra mile for those you love the most.
Prime Rib roast in a cast iron skillet

How to Cook a Prime Rib

  1. Dry brine your rib roast. One day before you plan to cook and serve your prime rib, coat the outside of the prime rib roast with a sprinkle of coarse sea salt.
  2. Apply the dry rub. No need to rinse off the salt that remains from the dry brine—just go ahead and rub your spices right on top of that lovely salty layer.
  3. Bring your meat to room temperature. After you’ve applied the dry rub, allow your meat to come to room temperature (this should take an hour or two).
  4. Cook your prime rib roast! Finally! Into the oven it goes, bone side down.
  5. Use a meat thermometer to test for doneness. We can’t stress this enough! How many holidays have you spent bent over a prime rib roast, poking it and saying “do you think it’s done?”,  “I don’t know, it looks done, but I’m not sure.” We all know, once you cut into that baby there is no turning back. Get yourself a meat thermometer (we’re big fans of this one) and take guesswork out of the equation.
  6. Serve. Bask in the glow of adoration, and the knowledge that you have made a lot of people (well, at least six) very, very happy.

A Note on Our Secret (Actually Not-So-Secret) Ingredient.

Yes, we are calling for a retro-but-so-good packet of Johnny’s Au Jus. I know what you're thinking. You’re using a prepackaged mixture to season your roast?! You better believe it. And here's why:

  1. It’s how our Moms made it.
  2. It makes the best drippings (which makes the best gravy).
  3. It's just really dang good.
Prime Rib with Roasted Garlic and Horseradish Cream Sauce served on plates

Man cannot live on prime rib alone—as much as some of us wish we could. When dinner is as showstopping as this one, we like to keep sides simple. Our Hasselback Potatoes elevate your festive meal into a true blue classic, or lighten things up with a generous platter of Roasted Cauliflower.

Prime Rib with Roasted Garlic and Horseradish Cream Sauce on a plate with potatoes and green beans

Holiday Roast for Every Occasion.

If you make our prime rib recipe, we’d love to hear about it! Be sure to snap a photo, add it to your Instagram feed or stories and tag us @themodernproper and #themodernproper if you do. Also, feel free to leave a comment on the post and tell your friends where you discovered the recipe.

Prime Rib with Roasted Garlic and Horseradish Cream Sauce

Serves 6

Prime Rib & Roasted Garlic

5-6 lb bone-in rib roast
4 tbsp coarse sea salt
3 tbps freshly ground pepper
1 tsp granulated garlic
1 tsp mustard powder
1 pack Johnny's Au Jus seasoning
1 tsp freshly chopped thyme
2 whole garlic heads
2 tbsp olive oil

Horseradish Cream Sauce

1/2 cup heavy whipping cream, chilled
1/2 cup sour cream
1/4 cup mayonnaise
3-6 tbsp prepared horseradish sauce (more if you like it hot)
2 tbsp fresh chives, chopped
1/2 tsp sea salt

Method

  1. For the horseradish cream sauce: whisk the chilled heavy cream in a small bowl by hand until soft peaks form. Carefully fold in the sour cream, mayonnaise, horseradish, chives and salt. Place in the refrigerator until ready to use. (Can be stored for up to one week.)
  2. To prepare the roast: 24 hours prior to cooking, coat the rib roast in the coarse salt. Place, uncovered, in a baking dish lined with paper towels. Return the meat to the refrigerator.
  3. The next day, two hours before cooking, remove the roast from the refrigerator. In a small bowl mix together pepper, garlic, mustard powder, thyme and ½ of the package of Johnny’s Au Jus powder. Rub the roast completely with the dry ingredient mixture. Allow to rest uncovered until the prime rib roast has come to room temperature.
  4. To prepare the garlic, slice off the top of the heads to expose the cloves but leaving the outer peel intact. Place each garlic head on a small piece of foil and drizzle with olive oil. Close the foil up tightly and place in the oven with the roast.
  5. Preheat oven to 450°. Place the roast, with bones underneath, in a roasting pan or heavy bottom skillet, such as cast iron. Cook the roast for 20 min. Without opening the oven, reduce the temperature to 325° and allow to cook for 12-14 minutes per pound for rare (15-17 for medium rare) or until the roast reads 115° with an instant read thermometer (120°-130° for medium rare). Remove the roast and the garlic from the oven and allow to rest for 20 minutes, this process with continue cooking the roast, so don’t skip it.
  6. Once you’ve moved the roast to a carving surface, place the roasting dish on the stove top and bring the dripping to a rapid boil, add the remaining au jus seasoning and 1 cup of water and whisk vigorously until reduced by half. Move to a serving dish.
  7. Using a sharp knife, carve the roast away from the bones and then in even slices for serving. Serve with horseradish cream, roasted garlic and au jus.

*There are many variables in achieving a perfectly cooked prime rib that cannot be controlled making it extremely important to use an instant read thermometer and not rely on cook time alone.