The Best Slow Roasted Prime Rib

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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.

Preparing a slow roasted prime rib is easier than you think. Don’t be scared of making this delicious and juicy standing rib roast. With just a few easy steps, the oven does most of the work for you.

This showstopper of an entrée is perfect to serve for holidays, special celebrations or just about any time you want to enjoy an awesome dinner. 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.

the ingredients for the best slow cooked prime rib

• prime rib roast (also know as standing rib roast)
• salted butter
• garlic cloves
• rosemary ~ fresh
• thyme ~ fresh
• parsley ~ fresh
• kosher salt
• freshly ground pepper
• prepared horseradish
• sour cream
• mayonnaise

A prime rib roast can be expensive. But they do go on sale a few times of the year. Easter and Christmas are holidays when you can get a great deal on the roast. Be on the lookout for sales and be sure to pick one up.

what size roast to buy

It can be confusing on just how big or small 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.

chef cooking tips for preparing a prime rib roast

• Take the prime rib out of the refrigerator at least 1 1/2 hours before roasting it. If the roast is not room temperature, it will take longer to cook. It will also cook at an uneven rate.
• Place the roast bone side done in the pan. The bones will act as a roasting rack.
• Make sure to rub all sides of the roast with the butter, garlic and herb seasoning mixture (recipe below) for the best over all flavor.
• A wireless meat thermometer is the easiest and most foolproof way to cook a perfect slow roasted prime rib. Place the probe into the center of the roast and set the thermometer for the desired temperature. See the list below for the internal temperature for prime rib.
• Start the roast off in a 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.
• 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.
• When ready to carve the roast, first cut off the bones. Then slice the roast into at least 1-inch thick slices. Pour any juices from the cutting board over the sliced meat.

what should the internal temperature of cooked prime rib roast be?

Depending on how you like your prime rib ~ rare, medium rare, medium or medium well ~ the meat will have a certain internal temperature. A wireless meat thermometer is the most foolproof way to make a foolproof slow cooked prime rib roast. The prime rib continues to cook after it is taken out of the oven so 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.

If you make this awesome slow roasted prime rib, I’d love hearing from you. Be sure to leave a comment and/or give this recipe a rating ~ I do my best to reply to all your comments. And snap a photo to post to Instagram. I’ll add the photos to my Insta stories as I love seeing all your creations.

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more delicious dinner entrees to try

• Lemon and Garlic Butter Shrimp Scampi
• Prosciutto and Provolone Stuffed Chicken
• Shrimp with Roasted Tomato Sauce and Goat Cheese
• Triple Cheese, Spinach and Sausage Lasagna

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