The Best Slow Roasted Prime Rib

This Slow Roasted Prime Rib recipe is absolutely the BEST! I never knew how easy it is to make prime rib until I made it for our Easter dinner. It's juicy and delicious every time. The butter, garlic and herb rub make this an entrée everyone will love.

This garlic herb butter rubbed prime rib is a showstopper. With it's creamy horseradish sauce it's perfect to serve for a holiday dinner, special occasions or just any time you want to enjoy an unforgettable dinner. Since a prime rib roast is typically 5-7 pounds, it's a great for a large family gathering or group of friends.

My favorite side dishes to serve with prime rib are cheddar stuffed potatoes, garlic butter mushrooms (the blue cheese in this recipe is fabulous along side the prime rib!) and honey mustard roasted Brussels sprouts. It's a meal that's unforgettable!

What's to love about this prime rib recipe

Preparing a 5 pound prime rib can be intimidating. But it's easier than you think. With just a few easy steps, the oven does most of the work for you. You'll love that this slow roasted prime rib recipe for the following reasons.

• A showstopper ~ Serving an entire roast makes for a dramatic dinner. Get ready for the oohs and ahhs.
• Unbelievable flavor ~ A prime rib muscle isn't heavily used. The result is extremely tender and juicy meat. The large fat cap surrounding the roast and the marbling throughout make for a piece of meat the is super flavorful and rich.
• Easy to prepare ~ Making a prime rib roast is easier than you think. There is little prep work to be done. And the oven and a wireless thermometer do most of the work.

Ingredients & substitutions

Gather the ingredients to make this great slow roasted prime rib recipe. If substitutions can be made to the ingredients, they're listed. Scroll to the recipe card for full quantities of the ingredients.

• Prime rib roast ~ Also know as standing rib roast or rib roast. They are sold as a bone-in rib roast or a boneless rib roast.
• Salted butter
• Garlic cloves ~ With a fabulous cut of meat such as this, skip garlic powder and use fresh garlic.
• Fresh rosemary ~ Fresh is best! Skip dried herbs in this recipe.
• Fresh thyme and parsley
• Kosher salt and fresh ground black pepper
• Prepared horseradish
• Sour cream
• Mayonnaise

What size prime rib roast should you buy?

It can be confusing on just how small or a prime rib roast to buy. The largest roasts have 6 rib bones and can weigh 12 to 16 pounds. That is one BIG roast! But smaller roasts are also available.

A good rule of thumb is to estimate 2 generous servings per bone. This means that a 4 bone prime rib roast is about 7 to 8 pounds and will serve 8 people.

The roast is also available boneless. But my preference is to get one with the bones attached. This will yield the most juicy and flavorful slow roasted prime rib.

How to slow roast prime rib

This is a brief overview of the recipe. Scroll to the recipe card for the complete instructions.

1. Take the prime rib out of the refrigerator at least 1 ½ hours before roasting it. If the roast is not room temperature, it'll take longer to roast and cook at an uneven rate.
2. Place the roast bone side down in a roasting pan. The bones will act as a roasting rack.
3. Rub all sides of the roast with the butter, garlic and herb seasoning mixture.
4. Place the temperature probe into the center of the roast and set the thermometer for the desired temperature.
5. Start the roast off in a very hot oven ~ 500 degrees F. This will make the outside of the prime rib a beautiful roasted brown. After 30 minutes, lower the oven to 325 degrees F to slow cook the roast for the most flavor. Also, this ensures that the center of the roast does not overcook. Cook the roast for an additional 11 to 15 minutes per pound.
6. When the prime rib reaches the desired temperature, remove it from the oven and place it on a cutting board. Cover with foil and let rest for 30 minutes. The roast will continue cooking and the juices will redistribute throughout the roast.
7. When ready to carve the roast, first cut off the bones. Slice the roast into at least 1-inch thick slices. Pour any juices from the cutting board over the sliced meat.

More dinner recipe ideas

One more thing

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Let me know by leaving a comment and a star rating below. Share it on Pinterest, Instagram and Facebook.

Thanks ~ Amy

Recipe

The Best Slow Roasted Prime Rib

This Slow Roasted Prime Rib is absolutely the BEST! It is so easy to prepare and is juicy and delicious every time. The butter, garlic and herb rub makes this an entrée everyone will love.

5 from 1 vote

Print Pin Rate

Prep Time: 1 hour hour

Cook Time: 1 hour hour 30 minutes minutes

Total Time: 2 hours hours 30 minutes minutes

Servings: 6 - 8 servings

Calories: 637kcal

Author: Amy Casey

Equipment

• wireless meat thermometer

Ingredients 

1x2x3x

• for the prime rib roast
• 1 standing prime rib roast with bones ~ 3 to 5 bones estimate 2 to 3 servings per bone
• 4 tablespoons salted butter softened
• 6 large garlic cloves finely chopped
• 1 tablespoon chopped fresh rosemary
• 1 tablespoon chopped fresh thyme
• 2 tablespoons chopped fresh parsley
• 2 teaspoons kosher salt
• 1 teaspoon pepper
• for the horseradish cream
• ¼ cup prepared horseradish
• 1 cup sour cream
• 2 tablespoons mayonnaise

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Instructions

• Remove roast from fridge: Remove the roast from the refrigerator 1 ½ hours before roasting.
• Prep oven: Preheat oven to 500 degrees F. Adjust the oven rack to the lower one-third of the oven. The roast should cook in the center of the oven.
• Make the rub: In a small bowl, combine the butter, garlic, rosemary, thyme, parsley, kosher salt and pepper.
• Prep the roast: Place the roast bone side down in a roasting pan. Rub the butter mixture on all sides of the roast. Insert a wireless meat thermometer into the roast, if using.
• Cook the roast: Roast the prime rib at 500 degrees F for 30 minutes. Lower the temperature to 325 degrees F. Continue roasting the prime rib for 11 to 12 minutes a pound for rare or 115 degrees F on the thermometer and 13 to 15 minutes per pound for medium rare or 125 degrees F on the thermometer. The temperature will continue to rise as the roast is out of the oven and resting.
• Rest the roast: Remove the roast from the oven and place it on a cutting board. Cover with foil and let rest for 30 minutes.
• Make horseradish cream: Combine the horseradish, sour cream, and mayonnaise in a small bowl. Set aside.
• Slice: After the resting time, cut the bones off the roast. Carve the roast into about 1-inch thick slices.
• Serve: Serve the prime rib with the horseradish cream.

Notes

The prime rib continues to cook and the temperature rises 5-10 degrees after it is taken out of the oven. Follow the temperatures below for a perfect prime rib roast.

Rare ~ the center of the roast is bright red and pinkish toward the exterior. Remove the roast from the oven at 115 degrees F. The temperature will rise to 120 degrees F as the roasts rests.

Medium rare ~ the center of the roast is very pink and and slightly brown toward the exterior. Remove the roast from the oven at 125 degrees F. The temperature will rise to 130 degrees F as the roasts rests.

Medium ~ the center of the roast is light pink and brown toward the exterior. Remove the roast from the oven at 130 degrees F. The temperature will rise to 135 degrees F as the roasts rests.

Medium well~ the center of the roast is brown as is the exterior. Remove the roast from the oven at 140 degrees F. The temperature will rise to 145 degrees F as the roasts rests.

Nutritional information is an estimate and based on the ingredients and cooking methods used in this recipe.

Nutrition

Serving: 1/8 of recipe | Calories: 637kcal | Carbohydrates: 6.9g | Protein: 36.4g | Fat: 50.7g | Saturated Fat: 22.6g | Cholesterol: 154mg | Sodium: 1864mg | Fiber: 0.7g | Sugar: 0.9g

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