How Long Do You Cook A 6 Pound Boneless Prime Rib Roast

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Boneless Prime Rib Recipe with a Garlic-Herb Crust

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Side dishes for boneless prime rib
How to buy prime rib
- How much prime rib will you need?
- What is prime rib called at the grocery store?
- How much is a boneless rib roast?
How do you cook boneless prime rib?
- Why is prime rib served rare?
- What is the perfect temperature to cook prime rib?
- How long do you cook a boneless prime rib?
- Should you cover prime rib while it's cooking?
- What about a bone-in rib roast?

I host Christmas dinner every year. My mom does Thanksgiving, my sister Jolie does Christmas Eve and I get Christmas Day. Jolie makes it fun, serving lots of different appetizers that we all graze on after the presents are opened (and we might sneak a few before and during, too).

But I get the easy part – making a big Christmas dinner for everyone.

I know you might think I'm crazy, but hear me out. Making a boneless prime rib is SO SIMPLE. I roughly calculate the time it will take for the roast to cook to the correct temperature so I know what time to put it in the oven. A leave-in thermometer tells me where the roast's temperature is at while it cooks, so I can keep an eye on it. And an alarm goes off when it's done!

I plan out my sides in advance and choose the ones that I can do most or all of the work ahead of time. Since the boneless prime rib is the star of the show, I can keep the side dishes simple. These are the sides that I've made in the past that have worked well:

Side dishes for boneless prime rib

Carrot Souffle – If you make any one of these side suggestions, let it be this one. Don't worry, it's not a "true" souffle and it really is easy! Everyone ALWAYS loves it, from toddlers to 80-year-olds. I promise you that everyone will be asking for the recipe.
Green Beans Almondine – This is another super easy recipe and it goes perfectly with boneless prime rib. You can even blanch the beans ahead of time, then reheat them in the pan with the butter and almonds. And the beans taste great at room temperature, so if they're ready a few minutes early, you don't have to panic.
Smashed Brussels Sprouts with Parmesan – Easy, delicious, not too fussy to make while doing other things. Not quite as easy as the Green Beans Almondine, but simple nonetheless.
Easy Mushroom Risotto with Gorgonzola – This recipe is easy, yes, but more hands-on than the previous sides I mentioned. But it is SO GOOD, so if you want to make a dinner splash, this one is perfect!
Garlic Green Beans & Portobellos (with Parmesan) – This one went over big when I served it the first year. It's partly make-ahead; you can blanch the green beans hours ahead then set them aside. Just before eating, saute the mushrooms then toss with the green beans just to heat them up. Easy and delicious!
Instant Pot Scalloped Potatoes – This is the quickest way I've found to make scalloped potatoes. Use your favorite shredded cheese or try it with a crumbled blue.

How to buy prime rib

How much prime rib will you need?

This will ultimately depend on how big a feast you're making. The rule of thumb is 1/2 pound if it's a feast, 3/4 pound if it's a dinner with a few sides and 1 pound if there's just a side to go with it.

Think about what you'll be serving. How many appetizers? How long will people be there before you sit down to eat? If guests arrive an hour before dinner and you have a huge spread of appetizers, people are going to be half-full before they even sit down. If you have one cheese and cracker tray and it's two hours until dinner, they might be a bit more hungry.

Having said all that, I usually go for a pound per person (unless I'm feeding 20 people, of course). I do that because I absolutely LOVE the leftovers from a boneless prime rib. We make garlic bread and use that for the bread on a prime rib sandwich with horseradish cream (YES, it's as good as it sounds)!

So go over what you think you'll need and worst case, you'll have some to enjoy in the coming days.

What is prime rib called at the grocery store?

Your boneless prime rib likely won't be labeled as such at the store. Other names for it are "standing rib roast" and "beef rib roast". When in doubt, ask the butcher! The last thing you want is to buy the wrong cut of meat.

How much is a boneless rib roast?

That's a difficult question to answer since prices are so different depending on where you live. I live on the U.S. East Coast and our boneless rib roasts are usually around $11-$18 per pound, depending on what grade the meat is.

Usually, around the holidays, rib roasts go on sale since they're popular at that time of the year. I usually wait to buy mine until the day before unless I've found a deal I just can't pass up.

You can also order a high-quality prime rib roast online. While I haven't done this myself (yet), I'm told that Porter & York's are great.

How do you cook boneless prime rib?

Why is prime rib served rare?

The biggest reason is that if prime rib gets overcooked, all the fat cooks out of the meat and it will become dry and tough. It doesn't have to be served rare, but IMO, anything over medium-rare should be avoided.

The great part about cooking a rib roast to medium-rare in the center (which is how I do it) is that the edge pieces will be more cooked. My dad, for example, prefers his prime rib well past medium-rare, so he gets the end pieces and everyone else gets the middle! It's not overcooked at this point, so the end pieces are still juicy and tender.

What is the perfect temperature to cook prime rib?

My personal belief is that boneless prime rib should be cooked to medium-rare and no more. Cook the roast to 120-125° F for rare, and 130-135° F for medium-rare.

Be sure to use a leave-in meat thermometer!! I can't stress this enough. The reason boneless prime rib is so easy is that the thermometer takes all the guesswork out of it. If I suddenly didn't have one, I'd choose something else to make for dinner, because I'd never take the chance on overcooking such a beautiful piece of meat.

How long do you cook a boneless prime rib?

The rule of thumb is about 15-20 minutes per pound of meat. This also depends on the temperature of your oven since the higher the temperature, the faster it will cook.

The method that I use cooks the roast at a high heat first, to lock in the juices and form a nice crust on its outside area. Then I reduce the temperature and cook it low and slow, which results in a juicy, tender roast. I usually cook an 8-pound roast, which takes about 3 hours from oven to table, including the time it will need to rest after cooking.

Should you cover prime rib while it's cooking?

Nope! Leave it uncovered so it can form a beautiful, flavorful crust.

What about a bone-in rib roast?

Go for a bone-in rib roast if you'd like! I have an AMAZING recipe for a bone-in prime rib roast with a garlic-peppercorn wet rub. That's usually my go-to recipe but I'm switching it up this year!

If you have any more questions about how to cook your prime rib, shoot me an email anytime at kristy@thewickednoodle.com. And Happy Holidays!

Ingredients

1 8-pound boneless rib roast
4 garlic cloves, minced
1/4 cup chopped fresh tarragon
1/4 cup chopped fresh parsley
3 tbsp chopped fresh thyme
1/3 cup chopped fresh rosemary
1 tbsp coarse salt
2 tsp freshly ground black pepper
1/2 cup butter, softened

Instructions

Bring the roast to room temperature (let it sit out for at least an hour or longer).
Preheat your oven to 450° F.
Mix together the garlic, chopped herbs, salt, pepper and softened butter in a small dish. Rub the mixture all over the top and sides of the roast.
Place the roast on a rack inside of a roasting pan. Place it in the oven and cook for 20 minutes.
Reduce the heat to 325° F. Continue cooking the roast until it reaches an internal temperature of 130° F.
Place the roast on a carving board and tent it lightly with foil. Allow the roast to rest for 20-30 minutes, then carve it and serve.

Notes

You can also make this roast with this Mustard, Garlic & Peppercorn Rub in place of the herbs. There's a recipe for Creamy Horseradish in that post, which is a fantastic addition for this herb rub, too.

Nutrition Information:

Yield: 10 Serving Size: 1
Amount Per Serving: Calories: 1328 Total Fat: 108g Saturated Fat: 46g Trans Fat: 0g Unsaturated Fat: 49g Cholesterol: 326mg Sodium: 1002mg Carbohydrates: 2g Net Carbohydrates: 1g Fiber: 1g Sugar: 0g Protein: 82g

This data was provided and calculated by Nutritionix.

Author
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Kristy Bernardo is the recipe creator behind The Wicked Noodle. She's a five-time cookbook author, has taught cooking classes to both kids and adults, and has been creating recipes for nationwide brands since 2009. She learned most of her cooking skills from her mom and grandmother, then honed those skills at boot camp at the Culinary Institute of America.