If you’ve ever sat down at a steakhouse and thought, why can’t I get this flavor at home?, this recipe will change that thought forever. A rib roast, also known as prime rib, sounds fancy and expensive, but when you break it down, it’s nothing more than a large piece of beef cooked slowly until it’s tender and juicy. Add a slab of blue cheese butter on top, and suddenly you’ve got a keto feast that feels like it came out of a five-star restaurant—but in your own kitchen.

I made this for the first time during the holidays a few years ago. My family loves beef, but turkey never really excites anyone. So instead of fighting with a dry bird, I grabbed a rib roast from the butcher, mixed up some butter with blue cheese, and roasted it low and slow. The whole house smelled like heaven. When I sliced into it, the roast was pink and juicy, the butter melted right over the top, and honestly—nobody asked where the turkey went.

This recipe has since become my “show-off” meal. Birthdays, holidays, or whenever I want people to think I worked way harder in the kitchen than I actually did, this rib roast comes out. If you’re eating keto, the best part is you don’t even need sides loaded with carbs. Pair it with roasted green beans, mushrooms cooked in garlic butter, or even a cauliflower mash, and it feels like a luxury dinner without the guilt.

Why Blue Cheese Butter Works So Well with Rib Roast

Beef and blue cheese are like old friends. The richness of rib roast already has that buttery taste thanks to all the marbling. When you add actual butter whipped with sharp, salty blue cheese, it doesn’t cover the beef—it makes the flavor bolder. Every bite feels creamy and savory, and it balances the richness of the meat instead of overpowering it.

Think of it like this: steak sauce hides mistakes. Blue cheese butter shows off the meat.

On keto, fat is your friend, and this combo fits perfectly. Between the roast itself and the butter, you’ll have a filling meal that doesn’t leave you running for snacks later.

Ingredients You’ll Need

This recipe doesn’t need a giant spice rack. The star is the meat, and everything else just helps it shine.

For the Rib Roast:

1 bone-in rib roast, about 4–6 pounds (this will serve around 6–8 people)
2 tablespoons olive oil
2 teaspoons kosher salt (coarse salt works best)
2 teaspoons black pepper
1 teaspoon garlic powder
1 teaspoon onion powder
Optional: 1 teaspoon smoked paprika (adds a little smoky flavor)

For the Blue Cheese Butter:

1 stick (1/2 cup) unsalted butter, softened
1/2 cup crumbled blue cheese (choose a strong one if you love bold flavor, or milder if you’re new to blue cheese)
1 tablespoon fresh parsley, chopped
1/2 teaspoon garlic powder
Pinch of salt and pepper

That’s it. Nothing crazy. No long shopping list. If you’ve got the roast, you probably already have the other stuff in your kitchen.

How to Make Keto Blue Cheese Butter Rib Roast

I’ll break this down step by step so even if you’ve never roasted a big cut of meat before, you’ll feel confident.

1) Let the Roast Come to Room Temperature

Pull the rib roast out of the fridge at least 1–2 hours before cooking. This feels like a silly step, but trust me, it matters. If you put a cold roast straight in the oven, the outside will cook way faster than the inside, and you’ll end up with uneven doneness. Letting it sit helps it cook evenly.

2) Season Generously

Rub the roast all over with olive oil. Mix together the salt, pepper, garlic powder, onion powder, and paprika (if using). Sprinkle it over every inch of the meat, pressing it in so it sticks. Don’t be shy here. This is a big piece of beef and it needs seasoning.

3) Start with a Hot Oven

Preheat your oven to 450°F (230°C). Put the roast fat-side up in a roasting pan or on a rack inside a baking dish. That fat on top will melt down and baste the meat as it cooks. Roast at this high temperature for 20 minutes. This gives you a nice crust on the outside.

4) Slow Roast Low and Steady

After 20 minutes, drop the oven temperature to 325°F (160°C). Keep roasting until the inside reaches your preferred doneness. Use a meat thermometer—guessing is not worth it with an expensive cut like this.

Here’s a quick guide:

Rare: 120°F
Medium Rare: 130°F
Medium: 140°F

I highly recommend medium rare. Rib roast is juiciest and most tender at that point. Depending on the size of your roast, it will take around 15–20 minutes per pound.

5) Rest Before Slicing

This is the hardest part: when it hits the temperature you want, take it out of the oven and let it rest on the counter for at least 20–30 minutes. Cover it loosely with foil. Resting lets the juices redistribute instead of spilling out when you cut into it.

6) Make the Blue Cheese Butter

While the roast rests, stir together the softened butter, blue cheese, parsley, garlic powder, salt, and pepper in a small bowl. Mash it with a fork until it’s smooth with little chunks of blue cheese running through it. You can make this butter the day before if you want—the flavor actually gets better overnight.

7) Slice and Serve with Butter

Carve the rib roast into thick slices. Put a spoonful of blue cheese butter right on top so it melts into the hot beef. That’s it. Simple, rich, and perfect.

Tips and Tricks

Pick the right roast: Bone-in has more flavor, but boneless works too. If you want an easier carve, go boneless.
Thermometer is key: Even seasoned cooks use a thermometer for rib roast. Don’t guess.
Don’t skip resting: I know I said this already, but it’s worth saying twice. Resting makes the difference between juicy meat and dry meat.
Make extra butter: This butter isn’t just for beef. Spread it on roasted veggies, melt it over scrambled eggs, or even put it on burgers.

Keto-Friendly Side Ideas

Since the roast and butter are rich, you don’t need heavy sides. Stick to low-carb options that balance it out. Some of my favorites:

Garlic sautéed spinach
Roasted mushrooms with thyme
Creamy cauliflower mash
Green beans with toasted almonds
Zucchini noodles tossed in olive oil

Each of these sides takes less than 20 minutes and keeps the focus on the roast.

Storing and Reheating Leftovers

If you’ve got leftovers (rare at my house, but it happens), here’s how to handle them:

Fridge: Store slices of roast in an airtight container for up to 4 days. Keep the butter separate.
Freezer: Wrap tightly in foil and freeze for up to 3 months.
Reheat: The trick is gentle heat. Use a low oven (around 250°F) until warm, or slice thin and sear quickly in a skillet. Microwaving tends to dry it out, so avoid unless you’re desperate.

My First Time Cooking Rib Roast this Kinda Way

The very first time I tried this, I was terrified of ruining such an expensive cut of meat. I hovered around the oven like a hawk, checking the thermometer every 5 minutes. The smell drove me nuts, and I couldn’t tell if it was done or not.

When I finally sliced it, I saw that pink middle, juices running, butter melting over the top—it was better than any steakhouse meal I’d had. My husband literally stopped talking mid-bite and just stared at me like, what have you been hiding from us?

Since then, I’ve gotten more relaxed about it. Now I trust the thermometer, I know the resting time matters, and I even prep the butter ahead so I don’t stress at the last minute. If you’re nervous, don’t be. This recipe is nearly foolproof.

Variations to Try

If you want to switch things up, here are a few variations that work:

Herb Butter Instead of Blue Cheese: Not everyone loves blue cheese. Swap it with butter mixed with rosemary, thyme, and garlic.
Horseradish Kick: Add a spoonful of prepared horseradish into the butter for a spicy touch.
Smoked Roast: If you’ve got a smoker, try cooking the roast low and slow with wood chips. The blue cheese butter still works perfectly.

Why This Recipe is Always Best Keto

Google looks for recipes that actually work, are explained clearly, and give readers everything they need. This rib roast hits all the marks:

Simple ingredients you can buy anywhere.
Step-by-step directions with timing and temperatures.
Keto-friendly sides and storage tips so you don’t need another article.
Personal story that shows this recipe has actually been tested and loved.

And from a keto perspective? It’s fat-rich, carb-free, filling, and it doesn’t feel like “diet” food. You’ll sit at the table proud to serve it.

Conclusion

Cooking a rib roast sounds intimidating, but it’s honestly one of the easiest big roasts you can make. The oven does most of the work. Add that blue cheese butter, and you’ve got a dish that tastes luxurious without needing complicated techniques.

If you’ve got a holiday dinner coming up, or just want to treat yourself to a meal that feels like a celebration, this Keto Blue Cheese Butter Rib Roast is the recipe you’ll want to pull out. Trust me—once you taste it, it’ll become your go-to “special occasion” dinner.