Keto Herb Crusted Prime Rib
A 6 pound boneless prime rib roast under a garlic herb butter crust, roasted to the USDA safe 145°F, with a quick au jus. Serves 10, with 45 g protein and 1 g net carbs per serving.
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If you are planning keto christmas recipes, start with the roast, because everything else on the table gets built around it. This keto herb crusted prime rib is the one I would put in the middle: a big, rosy rib roast under a thick coat of garlic herb butter, carved at the counter while everyone hovers. A 6 pound boneless roast serves 10.
In a lot of houses, the rib roast is the dish that only shows up once a year. People talk about it for weeks before. Somebody asks who is buying it, somebody else asks how big it needs to be, and somebody always wants to know if it is hard to cook. It is not. It is a big piece of beef, a thermometer, and a little patience.
Why a rib roast ends up on the Christmas table
A standing rib roast is a pricey cut that feeds a crowd. It is big enough that it only makes sense when the table is full, which is why it shows up at holiday dinners: it looks like an occasion, and it needs almost no work once it is in the oven.
The traditional plate is simple. Thick slices of beef, the juices from the pan spooned over the top, and something creamy and green on the side. Nobody is chasing a fancy sauce. The beef is the point. It never needed flour, a pastry crust or a glass of anything. It needed salt, heat and enough time to rest.
That is good news if you eat low carb, because the roast was already almost carb free. The only thing I changed is the part people usually ruin with flour: I skipped the gravy thickener and made a quick au jus from the pan juices and a cup of beef broth.
How I make this keto friendly Christmas dinner
I cook every recipe in my own kitchen before it goes on the blog, and a roast this size gets tested with a thermometer in it the whole way. The crust is plain and loud. Half a cup of soft butter, eight cloves of garlic, rosemary, thyme, parsley and a spoonful of yellow mustard, which helps the butter stay on the meat instead of sliding into the pan. No breadcrumbs, no wine, no Dijon.
You rub it over a dry roast and press it in with your hands. It is messy and a little bit fun. The roast goes in hot for 15 minutes so the outside browns, then the oven drops to 325 so the middle cooks gently. The kitchen smells like garlic and rosemary for the next hour and a half or so, and nobody wanders in without asking how long.
The part I take seriously is the temperature. USDA says beef roasts need to reach 145°F with a three minute rest, so that is where this recipe lands. Measure the roast with a thermometer pushed into the center of the thickest part and take it out of the oven when it reads 145°F, then let it rest at least 3 minutes before you slice. Pulling it earlier, around 130 to 140°F, gives you a rare or medium-rare roast that is not at the USDA safe minimum, so 145°F is the target here. A thermometer is not optional here. Time per pound is a guess, and a six pound roast is too expensive to guess on.
The numbers on a keto christmas dinner with prime rib
A 6 pound boneless roast serves 10. Each serving comes out at 45 g of protein and 1 g of net carbs, with 1 g of total carbs and no fiber, since there is almost nothing in the recipe that is not beef, butter or herbs. It is also a rich meal, at 85 g of fat and about 965 calories per serving. The numbers count the whole raw roast and every bit of the butter, including the fat that renders into the pan, so the real number on your plate is a little lower. It is better for the card to run high than low.
Because it is so low in carbs, it passes my keto test easily. The question is what goes beside it. If you want a green side that stays low carb, my low carb Christmas creamed spinach is the creamy spoonful that belongs next to this roast, and you can make it while the beef rests.
If you want to compare roasts, my low carb Christmas beef tenderloin is the leaner, quicker option for a smaller table. The prime rib is the one for a big crowd and a bigger appetite.

Keto Herb Crusted Prime Rib
- Prep
- 20 MIN
- Cook
- 2 HRS 5 MIN
- Total
- 2 HRS 45 MIN
- Serves
- 10
01Ingredients
02Gear & pantry
03Method
Tap a step when it's done. The next one lights up.
0 OF 9 DONE04Recipe notes
- 01Serves 10 from a 6 lb boneless roast (about 9.6 oz raw per person). Net carbs: 1 g total carbs minus 0 g fiber = 1 g net. Nutrition is calculated from the full raw roast weight and all of the butter, so the fat and calories run slightly high. Cook to temperature, not time: the USDA safe minimum for beef roasts is 145°F with a 3 minute rest, and a lower pull temperature leaves the roast rare or medium-rare. Leftovers: refrigerate within 2 hours, use within 4 days, reheat to 165°F.
05Nutrition
Per serving- Calories
- 965
- Protein
- 45G
- Net carbs
- 1G
- Fat
- 85G
- Fiber
- 0G
Net carbs are total carbs minus fiber. Numbers are estimates from the ingredients listed.
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Make ahead, storing and reheating
You can mix the herb butter a day ahead and keep it in the fridge; let it soften before you spread it. Season the roast and let it sit uncovered in the fridge overnight if you have the room, then take it out an hour or two before cooking so the middle is not ice cold.
Leftovers should go into the fridge within two hours of cooking, and the USDA says to use or freeze leftovers within four days and reheat them to 165°F. Slice what is left, keep the juices in a separate jar, and warm the slices in a covered pan with a splash of that jus so they do not dry out. Cold sliced prime rib the next day, with a bit of horseradish, is not a bad lunch either.
FAQ
Can I make keto Christmas recipes like this ahead of time?
The herb butter, the jus broth and your sides can all be ready the day before. The roast itself is best cooked the day you serve it, because it needs about two hours in the oven and the rest time gives you room to finish everything else.
What temperature should prime rib be for a keto Christmas dinner with prime rib?
For food safety, 145°F measured with a thermometer, followed by a three minute rest. A lower pull temperature leaves the roast rare or medium-rare and not at the USDA safe minimum, so take it out at 145°F.
Does this work as a keto Christmas menu centerpiece?
Yes. It serves 10 at 1 g net carbs per serving, so the sides are where you decide how low carb the plate stays.
Slice it thick, spoon the jus over the top, and put the creamed spinach right next to it. Somebody will ask for the end piece, the crustiest one, and they will not be the only one.
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