Prime Rib in a Roaster Oven
This Prime Rib in a Roaster Oven recipe provides an easy how-to for making prime rib roast in an electric roaster that goes down in history as the best-ever holiday meal.
This handy countertop appliance does one heck of a job at cooking up some luscious prime rib roast that slices into tender and juicy slabs of beef.
Prime Rib in an Electric Roaster
Until I cooked a prime rib roast in an electric roaster oven, my go-to method has always been cooking fool-proof prime rib in the oven using the 500 rule.
But then I heard you could make delicious prime rib in a roaster oven. Say what?
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I was skeptical. But because I always love a good cooking challenge and I’m always looking for roaster oven recipes, I had to put electric roaster prime rib to the test.
Turns out, prime rib roast made in an electric roaster is simply fantastic.
I was surprised to learn a roaster oven can produce prime rib magnificently browned and beautiful on the exterior with an interior that’s perfectly pink (medium rare) with just the right amount of tender bite.
What to love
- Cooking prime rib in your electric roaster oven means your oven is free to bake all those delicious side dishes and desserts for your holiday meal.
- Prime rib made in a roaster oven is so darn easy!
- An electric roaster cooks large hunks of meat in no time. Just wait until you try ham in a roaster oven.
Prime rib in a roaster oven recipe ingredients
- Prime rib roast: This recipe calls for a 10-12 pound prime rib roast which will include about 5 ribs, serving 10 people.
- Unsalted butter: I always use unsalted butter for cooking and baking. I don’t use salted butter for cooking since there’s no way to tell how much salt is in the butter.
- Garlic cloves: Crushed or minced garlic cloves combined with the spices and the butter makes a deliciously flavorful rub for the prime rib roast. It literally melts into the roast as it cooks providing flavor and beautiful browning.
- Seasonings: Black pepper, Seasoned salt, Onion powder or Granulated onion.
Recipe tips
- If you want a really good exterior “crust” on your prime rib, season it ahead and allow the roast to rest completely uncovered in the refrigerator for 24 hours.
- I like to have the butcher slice off the rib rack (the bones), then tie them back on for cooking the prime rib. This way you get all the flavor the bones provide, yet you can still lift the roast right off the bone rack, making slicing the roast a very easy process.
- Cooking times for this recipe will vary based on how your electric roaster oven cooks. As a general rule of thumb, a 12 lb. prime rib roast will take 12-14 minutes per lb. for medium-rare doneness.
How to cook prime rib in a roaster oven
Unwrap the prime rib roast from the packaging and pat dry with paper towels. Place the prime rib, fat side up, onto a large-rimmed baking sheet.
Combine the seasoned salt with the black pepper in a medium bowl, then add the softened butter and garlic, combining well until you have a smooth paste.
Use your fingers to spread the seasoned garlic butter all over the prime rib roast, pressing it into all the nooks and crannies.
If there’s time, place the buttered roast into the fridge for 24 hours. Make sure it is uncovered, allowing it to season during this resting time.
This allows the seasoning blend to penetrate the meat, drawing out moisture on the surface.
This will help it get a caramelized and crusty exterior, staying juicy and tender on the inside.
When you are ready to cook the roast, remove it from refrigeration to let rest on the counter, uncovered, for at least 2 hours.
This allows the fat and meat juices that coagulate at the center of the meat to release and also gives the protein fibers of the beef time to relax.
The prime rib can cook much more evenly, providing the delicious eating experience we all long for.
Preheat the electric roaster to 450 degrees F. Some roasters only go as high as 425 degrees F, so use that. Place the rack into the bottom (no liquid is added to the roaster oven).
After 10-12 minutes, the roaster should be nicely preheated. Place the prepared prime rib roast onto the rack.
Do not place any liquid in the electric roaster.
Cooking the prime rib roast in the electric roaster without liquid keeps the exterior of the roast brown and caramelized.
Adding liquid to the electric roaster makes the prime rib steam as it cooks.
It will still be delicious but won’t have the good “crusty” exterior desired when enjoying prime rib.
If you are using an electronic meat thermometer, insert the probe directly into the center of the prime rib, taking care not to touch any bones.
Close the roaster lid and cook the prime rib on high (425-450°F) for 25-30 minutes to roast the exterior until it is a deep golden brown color.
Reduce the roaster temperature to 350 degrees F.
Continuing to cook the prime rib for 10-12 minutes per pound, or until it reaches 120-125 degrees F. at the center, about 2 more hours.
This time will vary depending on how your electric roaster cooks and the size of your prime rib.
It’s recommended to cook prime rib roast until it reaches rare or medium rare in doneness for the best eating experience.
You can always cook slices of prime rib a little bit more, but once it’s overcooked, there’s no going back.
Remove the thermometer probe from the rib roast, then lift the prime rib from the roaster and place it onto a large cutting board.
Cover the prime rib with foil and let it rest for at least 15-30 minutes.
The bigger the prime rib, the longer the resting period you will need since this resting time allows the protein fibers of the meat to relax, making for a tender eating experience.
As the prime rib rests, it also continues to cook from residual heat, raising the internal temperature.
After the prime rib has rested, it’s time to cut the strings that are holding the rib rack onto the roast. Once the strings are cut, you can then lift the roast from the bones to slice it.
After you lift the roast from the rib rack, place it cut-side-down onto the cutting board, then slice it into thick slabs.
You will see that not having to cut around the bone rack makes the task of slicing so much easier.
Serve warm with horseradish sauce on the side.
Prime rib temperature chart
- Rare: 125 degrees F., 10 to 12 minutes per pound, cooking time approx. 2 1/4 – 2 1/2 hours
- Medium Rare: 135 degrees F., 12 to 14 minutes per pound, cooking time approx. 2 1/2 hours
- Medium: 140-145 degrees F., 15 to 17 minutes per pound, cooking time approx. 3 hours
- Medium Well: 150-155 degrees F., 17 to 19 minutes per pound, cooking time approx. 3 1/2 hours
What’s the secret to cooking juicy prime rib in an electric roaster?
My best advice is this: don’t lift the lid while the prime rib is cooking. This lets the accumulated heat inside the roaster escape!
You’ll want to invest in and use a digital probe instant-read meat thermometer.
It will allow you to monitor the internal temperature of the prime rib roast without ever lifting the roaster lid. This is so essential!
What’s wrong with well-done prime rib?
Well-done prime rib roast tastes like roast beef. Rare or medium-rare prime rib tastes like steak.
Which one do you really prefer?? I think I know!
Why should you cook prime rib just to rare or medium-rare doneness?
It’s a good idea to cook prime rib roast just until it reaches rare or medium-rare doneness.
You can always cook slices of prime rib a little bit more, but once it’s overcooked, there’s no going back.
What to do with prime rib leftovers
Chopped leftover prime rib would be delicious added to breakfast potatoes or to make philly cheesesteak bread. If you diced it small, you could make delicious roast beef wellington packets in a heartbeat. Loaded skillet fries could easily be made with prime rib.
Substitute prime rib for beef tenderloin to make sandwiches or sliders.
Prime rib nachos would sure make a great gameday appetizer. In short, substitute leftover prime rib in any recipe that calls for cooked beef.
What to do with prime rib bones
Yep, don’t forget to use those leftover bones to your advantage.
Roast them in the oven to enhance the flavor. Then add them to a pot of water with onions, celery, garlic and carrots.
Simmer until you have a delicious, rich bone broth. Bone broth makes wonderful soups and stews.
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Prime Rib in a Roaster Oven
Ingredients
- 10 lb. prime rib roast, about 5 ribs, bone rack removed and tied back on for roasting
- 1/2 cup unsalted butter softened
- 1 Tbs. seasoned salt
- 1 Tbs. black pepper
- 1 Tbs. onion powder or granulated onion
- 3 big cloves garlic, minced or crushed
Instructions
- Unwrap prime rib from packaging and pat dry with paper towels. Place the prime rib, fat side up, onto a large rimmed baking sheet.
- Combine the seasoned salt with the black pepper in a medium bowl, then add the softened butter and garlic, combining well until you have a smooth paste.
- Use your fingers to spread the seasoned garlic butter all over the prime rib roast, pressing it into all the nooks and crannies.
- If there’s time, place the buttered roast into the fridge for 24 hours, uncovered, allowing it to season during this resting time.
- When you are ready to cook the roast, remove it from refrigeration to let rest on the counter, uncovered, for at least 2 hours.
- Preheat the electric roaster to 450 degrees F. (some roasters only go as high as 425 degrees F so use that), placing the rack into the bottom.
- After 10-12 minutes, the roaster should be nicely preheated. Place the prepared prime rib roast onto the cooking rack.
- Cover the roaster with the lid. Cook the prime rib roast on high (425-450°F) for 25-30 minutes or until the exterior of the beef is deep golden brown.
- Reduce the roaster temperature to 350 degrees F., continuing to cook the prime rib for 10-12 minutes per pound, or until it reaches 125 degrees F. at the center, about 2 more hours. (This time will vary depending on how your electric roaster cooks.)
- Remove the prime rib from the roaster and place it onto a large cutting board; cover the prime rib with foil and let it rest for rest for at least 15-30 minutes after you take it out from the roaster.