If you’re planning to cook something bold, hearty, and low in carbs, maybe for Christmas, maybe for Sunday dinner, or just because you’re feeling fancy, this keto prime rib roast recipe with creamy horseradish sauce checks every box.

We’re talking juicy rib roast, cooked slow and low until it’s got that perfect pink center, topped with a garlic horseradish cream sauce that’ll punch up the flavor like nobody’s business. It’s that kind of recipe that gets everyone quiet at the dinner table (in a good way).

You don’t need to be a pro chef. If you’ve got a roasting pan, a meat thermometer, and some time, you’re all set.

What You’ll Need for Horseradish Cream Prime Rib (Nothing Crazy Here)

For the Rib Roast:

1 standing rib roast (4 to 6 ribs, bone-in, about 8 to 10 pounds)
Salt (use more than you think)
Black pepper
3 tbsp olive oil or softened butter
Fresh garlic, 6-8 cloves, minced
Fresh rosemary or thyme (optional, but adds a nice aroma)

For the Creamy Horseradish Sauce:

1 cup sour cream
1/2 cup prepared horseradish (drain extra liquid)
1 tsp Dijon mustard
1 tsp white vinegar or lemon juice
1/2 tsp garlic powder or roasted garlic
Salt and pepper to taste

If you’re the kind of cook who likes a sauce for beef roast to dip every bite, you might want to double that horseradish cream recipe. It goes fast.

Making The Meal (Step-by-Step)

Step 1: Let the Meat Chill… or Not

Pull the rib roast out of the fridge a good 2 hours before you plan to roast it. Letting it come up to room temp helps it cook more evenly. Cold beef straight into a hot oven can mess up the doneness levels and dry the outside before the inside’s ready.

Give it a generous rubdown with salt, pepper, garlic, and oil or butter. Press those herbs on if you’re using them. You want it coated like it’s heading into battle.

Step 2: Start the Oven Low and Slow

Set your oven to 225°F (around 105°C). No shortcuts. Low heat is what makes this prime rib roast melt-in-your-mouth tender.

Place the roast bone-side down on a rack inside a roasting pan. If you don’t have a rack, roll up some foil into a coil and set the meat on that. Works just as well.

Roast until the internal temp hits about:

115°F for rare
125°F for medium-rare
135°F for medium

Use a meat thermometer. Don’t guess. It usually takes about 3-4 hours for a medium-rare roast, depending on the size.

Step 3: Rest and Blast

Once it hits temp, take the roast out, tent it with foil, and let it rest for 30 minutes. Now crank your oven up to 500°F.

Right before serving, pop the roast back in the oven for about 10 minutes. This gives you that golden, crispy crust. The contrast between the crust and the soft, juicy middle is what makes people go back for seconds (and thirds).

The Star of the Show: Creamy Horseradish Sauce for Prime Rib

Some folks like their beef with gravy. But once you try this cream horseradish sauce, there’s no going back. It’s bold, a little sharp, but still creamy enough to balance the richness of the meat.

This is one of those recipes with horseradish sauce that works with almost any beef—tenderloin, roast beef, even leftover steak. And it takes five minutes to make.

Just mix together all the sauce ingredients in a bowl. Adjust the heat by adding more or less horseradish. Taste and tweak as needed. Want it extra rich? Use mayo instead of sour cream. Feeling garlic-heavy? Add more roasted garlic.

Let it chill in the fridge while your roast is cooking. The flavor gets better as it sits.

Leftover Game Plan (Don’t You Dare Toss It)

That leftover prime rib makes killer sandwiches. Load it up on low-carb bread with some extra horseradish cream sauce for roast beef, maybe a few caramelized onions or a slice of cheddar.

Or go full keto beef tenderloin mode and make a beef salad bowl with avocado, spinach, crumbled blue cheese, and a drizzle of that leftover tenderloin sauce. It’s like steakhouse lunch at home.

What If You’re Cooking Tenderloin Instead?

If you’re skipping the bone-in rib roast and cooking a tenderloin, this horseradish cream still works perfectly. In fact, beef tenderloin sauce recipes often lean on horseradish because the cut is leaner and needs that kick.

Same deal—roast it gently, rest it, then sear if you want a crust. That garlic horseradish sauce makes it taste like you spent double the money.

This one’s also great for Christmas tenderloin dinners when you want a wow-factor meal without a lot of fuss.

More Sauce Options If Horseradish Isn’t Your Thing

Not everyone’s a fan of that zingy horseradish heat, and that’s okay. If you’re looking for other sauces for roast beef, try these:

Red wine reduction: Classic and elegant. Just simmer red wine, beef broth, garlic, and a sprig of thyme until thick.
Creamy mushroom sauce: Sauté mushrooms with butter, garlic, a splash of cream, and a little white wine.
Chimichurri: If you like bright and tangy, this mix of parsley, garlic, olive oil, and vinegar is a fresh option.
Garlic herb butter: Melt butter with minced garlic and herbs, then drizzle it over sliced meat. Simple, no-fail, always good.

If you’re collecting tenderloin sauce recipes or planning a roast beef sauce recipe book of your own, these ones are solid staples.

Tips to Nail It Every Time

Don’t skip the rest time. This lets the juices settle and keeps the meat tender.
Invest in a meat thermometer. Overcooked rib roast is a crime against beef.
Salt it more than you think. Big cuts need big seasoning.
Make the sauce ahead. It keeps for up to a week in the fridge.
Roasted garlic makes everything better. If you’re not roasting garlic for your sauce, you’re leaving flavor on the table.

Here’s how to make a quick roasted garlic recipe: slice the top off a head of garlic, drizzle with olive oil, wrap in foil, and roast at 400°F for 30-40 minutes until golden and soft. Squeeze it out like toothpaste and mix it into your horseradish cream.

Conclusion

So whether you’re roasting up a holiday rib roast, planning a special Christmas tenderloin, or just want a killer sauce for beef roast, this keto-approved meal brings the goods.

The creamy horseradish sauce ties it all together—rich, sharp, simple, and unforgettable. And that’s the goal right? Food that tastes great and feels good to serve.

You don’t need fancy ingredients. You don’t need a French cooking degree. Just good meat, a hot oven, and a sauce that wakes everything up.

And if someone at the table asks you how to make creamy horseradish sauce like that, just wink and tell ‘em it’s a family secret.