Make Prime Rib Sandwich with your prime rib leftovers. Top the prime rib with grilled onions, peppers and slice cheese for a quick and easy dinner idea.

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If you have made our Grilled Prime Rib Recipe chances are you have leftovers. What better way to use than in this sandwich recipe. Everything is heated easily on the Blackstone Griddle to create a quick and easy lunch or dinner idea.
We love using leftover meat to make hearty sandwiches. Try these family favorite recipes so your leftovers do not go to waste – Blackstone Chicken Philly Cheesesteak,Blackstone Chopped Cheese Sandwich, Italian Steak Sandwich, Grilled Hot Honey Chicken Sandwich, Chicken Bacon Ranch Sandwich and Blackstone Turkey Reuben Sandwich.
Table of Contents
Why This Recipe Works
We love making extra prime rib so we can enjoy this sandwich with the leftovers. Everything heats perfectly on the large flat surface griddle to create the best prime rib sandwich.
The ingredients are simple and you can make your sandwich with a variety of toppings. Add your favorite side dishes for a complete meal idea.
Ingredients

- Mayonnaise – Add a tablespoon of sour cream to the mayo for added flavor.
- Dijon Mustard – You can also substitute with Yellow Mustard
- Cloves garlic, minced – Learn How to Mince Garlic with these simple steps.
- Avocado oil, divided – Check out Best Oil to Season Blackstone Griddle if you are out. Make sure to use a High Point Oil.
- Sliced Onions – You can also use yellow onions or red onions
- Leftover Prime Rib Roast, thinly sliced – Feel free to substitute with steak or leftover roast beef
Scroll to the bottom for the full recipe and ingredients in the recipe card.
Variations Ideas
- Bread Variation – You could also use baguettes, French Bread, artisanal loaves, hoagie roll or even hamburger buns for a different variety of textures and flavors.
- Veggies – Our favorite way to make this leftover prime rib sandwich recipe is with peppers and onions. But you can also top with fresh arugula, mushrooms, or fresh spinach.
- Slices of Cheese – Substitute slices of provolone cheese with swiss cheese or colby monterrey jack.
- Toppings – Mayo works great but a creamy horseradish sauce is my husbands favorite way to serve this sandwich.
Step by Step Instructions
- Step 1 – In a small bowl, mix together mayonnaise, Dijon mustard, and minced garlic. Set aside.

Step 2 – Heat 1 tablespoon of oil on a Blackstone grill over medium heat. Add the sliced onion and green bell pepper, season with salt and black pepper, and cook until they are soft, tender and slightly caramelized, about 7-10 minutes. Push to a cooler side of the grill.

Step 3 – Add the remaining tablespoon of oil to the grill. Add the thin slices of prime rib and cook for a few minutes just until heated through. Be careful not to overcook, as the meat is already cooked.

Step 4 – Place each slices of bread on the grill to brown them for 1-2 minutes. Remove from the grill and spread the mayonnaise and mustard mixture on top.

Step 5 – Divide the warm prime rib into 4 sections. Top each section with the sweet caramelized onions and bell peppers and a slice of the provolone cheese. Let them heat for a few minutes to melt the cheese.
- Step 6 – Then place each individual section on the browned rolls. Serve warm and enjoy!
Recipe Tips
- Prime Rib – After you have cooked prime rib, I recommend going ahead and slicing it to store. This will make it easier to quickly reheat on the griddle for a quick dinner idea.
- Bread – We like to taste and crispy texture that the griddle gives the bread, but you can also toast in the oven. Top the bread with butter and place on a baking sheet and reheat under the broiler for a few minutes.

Serving Suggestions
These prime rib sandwiches are rich, hearty and can be served as they are. But I like to add a few side dishes for a complete meal idea. You can serve with a side of chips or serve with one of our favorites.

Frequently Asked Questions
Yes, you can easily reheat the meat and cheese in a large skillet or a cast iron pan. Toast the rolls in the oven and add your favorite toppings such as horseradish mayo to enjoy your prime rib the next day.
Store the shaved prime rib in an airtight container in the refrigerator for up to 3-4 days.
Yes, you can freeze the prime rib. Wrap the sliced prime rib with plastic wrap and then foil and place in a zip lock freezer bag. It will stay fresh for up to 3-4 months.
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If you make this Blackstone Prime Rib Sandwich Recipe, please leave us a comment or a star review. We love to hear from you.

Prime Rib Sandwich
Ingredients
- 4 tablespoons mayonnaise
- 2 tablespoons Dijon mustard
- 2 cloves garlic minced
- 2 tablespoons avocado oil divided
- 1 large onion thinly sliced
- 1 green bell pepper thinly sliced
- 1 pound leftover prime rib thinly sliced
- Salt and pepper to taste
- 4 sandwich rolls or ciabatta bread
- 4 slices provolone cheese
Instructions
- In a small bowl, mix together mayonnaise, Dijon mustard, and minced garlic. Set aside.
- Heat 1 tablespoon of oil on a Blackstone grill over medium heat. Add the sliced onion and green bell pepper, season with salt and pepper, and cook until they are soft and slightly caramelized, about 7-10 minutes. Push to a cooler side of the grill.
- Add the remaining tablespoon of oil to the grill. Add the thinly sliced prime rib and cook for a few minutes just until heated through. Be careful not to overcook, as the meat is already cooked.
- Place each roll on the grill to brown them for 1-2 minutes. Remove from the grill and spread the mayonnaise and mustard mixture on top.
- Divide the warm prime rib into 4 sections. Top each section with the cooked onions and bell peppers and a slice of the provolone cheese. Let them heat for a few minutes to melt the cheese.
- Then place each individual section on the browned rolls. Serve warm and enjoy!
Delicious and easy to make!