Prime Rib Sandwich

This Prime Rib Sandwich recipe is absolutely THE best way to use up leftover prime rib. Just imagine shaved prime rib that you warm up, top with sautéed onions and melted provolone cheese, then nestle in a toasted hoagie bun. YUM.

Trust me, you won't find a better leftover prime rib recipe.

Have you ever found yourself asking the question, "What can I do with leftover prime rib?" If so, the answer is simple: MAKE PRIME RIB SANDWICHES!

Phil and I make it a point to have date night a couple times each month. We usually go with Date Night Prime Rib. It comes out perfect every time and—bonus—you get some truly incredible au jus. Extra bonus: we always have leftovers. Yay!

I have to admit: a big reason that we make prime rib is with the next day's leftover prime rib sandwiches in mind. Two meals in one: how great is that?!

You can also use leftovers from my Reverse Seared Thick Ribeye Steak recipe.

I serve this sandwich warm. Re-warmed, shaved prime rib has so much more flavor than when it's served cold or even at room temperature. But the real questions is . . .

. . . how do you reheat shaved prime rib so you don't lose the nice pink tenderness you worked so hard to create the night before? No worries! I'll cover this below.

You top the warmed prime rib with melted provolone cheese and sautéed onions and pile it all into a toasted bun. And don't forget about the homemade au jus: this unctuous, beefy broth brings it all together.

Trust me: once you make these prime rib sandwiches, you'll agree that this is the only leftover prime rib recipe you need. They are simply amazing—truly restaurant-quality stuff.

Read on: I'll walk you through the exact steps for making a prime rib sandwich that will completely eclipse anything you've ever eaten in a restaurant.

Interested in other amazing sandwiches? Check out my Reuben & Grilled Cheese Sandwich recipes.

How to make a prime rib sandwich

All you need is leftover prime rib, onions, provolone cheese, and a good hoagie bun. If you want to add or substitute some of the toppings, go nuts.

How to slice prime rib

Start by thinly slicing your leftover prime rib. You want extremely thin or even shaved meat.

Thin slices are important: even prime rib has some gristle or tough fat running through it. When the slices are thin enough, you won't notice! BONUS: thinner slices have a bigger surface-to-volume ratio, which, translated from Geek, means more surface to pick up flavor!

The best way to thinly slice leftover prime rib is to make sure the meat is cold. Cold meat is sturdier and will not wobble around as you slice it.

In fact, I sometimes put the meat in the freezer for about half an hour so it firms up and is easier to work with.

Using a sharp butchers knife, slice the prime rib as thinly as possible. Slice as much as you need and set aside at room temperature. (No more than one hour, though!)

Or, you could go my husband's route and buy a meat slicer. (Ugh, one more single-purpose kitchen tool!)

On a positive note, it does produce consistent shaved slices and saves a bit of time. But it's definitely not necessary.

Sauté the onions

Sautéed onions are wonderful on prime rib sandwiches.

I thinly slice some sweet Vidalia onions and sauté them in a skillet with olive oil until they begin to turn golden-brown, which takes about 8–10 minutes.

Reheat the prime rib slices

In the same skillet as the onions, add the shaved prime rib. Stir in with the onions for no more than 30 seconds: this is just long enough so the meat begins to warm up.

This short reheat time is critical to ensuring you don't overcook your meat and lose the pink doneness from the night before.

Add the provolone cheese

In the same pan, add your provolone cheese (or any melty cheese you want) to the top of the prime rib and onion mixture. You can use slices or grated cheese.

Turn off the heat and cover immediately. Allow the residual heat from the mixture and the skillet to melt the cheese and continue to reheat the prime rib.

Toast the bun

While the cheese is melting, put your hoagie bun into your oven for a light toast, approximately 3-4 minutes.

Assemble the prime rib sandwich.

To serve, I just place a spatula-full of the cheese, meat, and onion mixture inside a toasted bun.

Serve as a sandwich or open-faced: it's your call. Just make sure to include a ramekin of au jus for dipping.

My Date Night Prime Rib Roast recipe makes perfect homemade au jus in addition to the fantastic prime rib. I encourage you to use this recipe the night before.

No au jus? No problem! Just mix a tiny bit of horseradish with a 1 to 1 ratio of mayonnaise and sour cream, and slather that on the hoagie roll. Or offer both!

What goes with prime rib sandwiches?

Check out some of these easy side dishes:
Creamy Pasta Salad
Chimichurri Pasta Salad
Easy Greek Pasta Salad
Cucumber-Onion-Tomato Salad
Or try an easy dessert, Cast Iron Chocolate Chip Cookie

And there you have it. The most awesome leftover prime rib sandwich you will ever have. I hope you love it!

P.S. If you need more inspiration for using up your leftovers, pop over and check out the easy dinner ideas in my article, Using up Leftovers!

Related Content

Date Night Prime Rib: A small roast provides 2 giant servings for a romantic Date Night or Valentine’s Day dinner, plus plenty of leftovers to slice up thinly for prime rib sandwiches. Easily adaptable to larger roasts to feed a crowd. 

Best-ever Reuben Sandwiches: Reuben sandwiches are practically mandatory in my house after the requisite Corned Beef-fest on St. Paddy’s day. They’re easy to put together and oh-so-melty-good.

Grilled Cheese Sandwiches: This method for making grilled cheese sandwiches ensures that the inside is ooey-gooey melty, while the outside is golden and crispy.