Whether you are celebrating a holiday like Thanksgiving or Christmas, or you're just feeling fancy, prime rib makes an amazing meal. Don't let any of it go to waste by making this leftover prime rib sandwich recipe. It doesn't feel heavy after a fancy meal and will satisfy everyone.
Prime rib sandwiches are a great way to enjoy leftovers. They're quick to assemble, but flavorful and satisfying. Make them more gourmet with a slightly tangy horseradish sauce that will make you completely okay with not having au jus.
How Long Are Prime Rib Leftovers Good For?
Prime rib leftovers are best eaten within two to three days of cooking. However, with a good airtight container, they will stay fresh in the refrigerator for up to five days. The more well done your prime rib is when you refrigerate it, the longer it will last. If you roast your prime rib to the typical rare to medium rare, potential bacteria has a better chance of growth. It’s one of those situations of being better safe than sorry. Make this prime rib sandwich recipe sooner than later.
How To Use Prime Rib Leftovers
Since a prime rib roast is such a pricey cut of beef, you want all of the leftovers to be relished. One of my favorite ways is a prime rib sandwich. If I feel lazy, I can eat it cold. If I feel more gourmet, a quick toasting under the broiler makes a crusty hot sandwich. Another reason I love making this prime rib sandwich is that it doesn’t overcook your leftovers. Many leftover prime rib recipes cook it beyond the beautiful rare to medium rare doneness you worked so hard for. This one, however, focuses on retaining it. Even if you choose to make your sandwich hot, the broiler keeps the cook time as brief as possible.
Tips For Making The Best Prime Rib Sandwich with Horseradish Sauce
Prime rib and horseradish sauce are a classic pairing. This horseradish sauce on this prime rib sandwich however has a slight variation. It is subtly muted by sour cream, while getting a flavorful boost from the roasted garlic. The secret ingredient though is the white balsamic. It’s there to just lightly boost the brightness of the sauce and allow the flavors to shine through. (Like lemon juice with berries.) If you really want to go above and beyond, these culinary skills and techniques will take your prime rib sandwich to a new level.
- How To Make Roasted Garlic. This goes through the details of how to make roasted garlic perfectly. If you overcook it, it is hard to remove from the head. If you undercook it, it doesn’t bring enough flavor to the horseradish sauce. Make sure you get it right.
- Make Perfect Caramelized Onions. Perfectly done caramelized onions leave nothing behind in the pan and have no scorch marks. Find out how to control your cooking so that your caramelized onions have excellent flavor AND texture.
If you know you are going to make this prime rib sandwich recipe, I recommend making your roasted garlic and caramelized onions ahead. That way you don’t spend multiple days hanging out in your kitchen.
Leftover Prime Rib Sandwich Recipe
If you want to make this prime rib sandwich hot, I recommend using your broiler on a medium or low setting. (If your broiler has settings.) Assemble the sandwiches without the baby kale and place them on a baking sheet. Cook them in the middle of the oven for two to three minutes, or until heated through. After you’ve removed them from the oven, carefully open the sandwich and add the greens. The residual heat from the sandwich will warm them up for you.
Want a free printable grocery list for this leftover prime rib sandwich recipe? Get it HERE.
Use this grocery list to help simplify shopping. Everything is listed in standard grocery store amounts. If no size is specified, even the smallest package will provide more than enough.
Happy Cooking! 🙂
Prime Rib Sandwich with Horseradish Sauce
- 2 large sweet yellow onions, peeled and sliced
- 4 Tablespoons butter
- 1 baguette
- 1 pound cooked prime rib roast, sliced thin
- 2 cups baby kale, or other leafy green
- ½ cup sour cream
- 1 Tablespoon cream style horseradish
- 1 teaspoon white balsamic
- 3 heads roasted garlic
- olive oil, as needed
- 1 Tablespoon fresh thyme
- salt and pepper , to taste
- Preheat the oven to 425°F. Cut the top off of the garlic heads and drizzle them lightly with olive oil. Place them on some aluminum foil and fold the foil into a packet. Roast for 45 minutes, or until the cloves are caramelized and starting to come out of the head. Open the foil packet and let the garlic cool to room temperature. Remove the cloves from the head.
- In a large skillet over medium heat, melt the butter and add the onions. Reduce the heat to low and cook until the onions are golden brown, stirring occasionally. When done correctly, this should take about 30 minutes. Let cool to room temperature.
- In a blender or food processor, add the sour cream, balsamic, roasted garlic cloves and horseradish cream. Pulse until the roasted garlic is incorporated. Stir in the fresh thyme and season with salt and pepper, adding any extra horseradish cream to your preference. Set aside.
Prime Rib Sandwich
- Remove the ends from the baguette and cut it into four equal pieces; about four inches long. Carefully slice horizontally into the bread (but not all the way through) to open it up.
- Slather the inside of the baguette with the horseradish sauce. Place a layer of baby kale, followed by 4-6 thin slices of prime rib. Dollop caramelized onions on top and add some fresh cracked black pepper. Close the baguette around the sandwich and serve.