If you’re wondering what to do with leftover prime rib, this Prime Rib Patty Melt recipe is a great option! It combines all the rich, buttery flavors of a classic diner melt with the buttery soft texture of perfectly cooked prime rib.
Patty Melt Sandwich
Like this prime rib French dip and prime rib Philly cheesesteak sandwich, I kept the beef in thick slices vs. shaving or thinly slicing to keep the integrity of the prime rib roast itself. My prime rib re-heating method keeps the meat as tender as it was on the day it was cooked.
Popular Prime Rib Recipes to consider making include my original Prime Rib Roast, Reverse Seared Prime Rib, or Smoked Prime Rib.
All the testing I performed, when creating this original leftover prime rib recipe, utilized leftovers from a roast made with this prime rib dry rub.
Ingredients and Substitutions
Here are the main ingredients needed to make a prime rib patty melt. The full list can be found in the recipe card.
- Leftover Prime Rib: I created and tested this recipe using one 1/4″-1/2″ slice of beef from a leftover prime rib roast. You can also use shaved beef or thin slices if you prefer.
- Cheese: Swiss is traditional, but provolone, cheddar, or Havarti all work beautifully.
- Bread: Classic rye or marble rye bread gives that signature patty melt flavor.
- Onions: Slowly caramelized onions add the signature sweet and savory depth. Try not to rush this step
- Optional Sauce: Horseradish sauce, Russian Dressing, or Dijon mustard adds a tangy contrast to the rich beef.
Reheating Prime Rib
During recipe testing, I found reheating the prime rib steak on the stovetop, with a splash of beef broth, beef au jus, or au jus mix, works the best. It’s not only extremely quick, but keeps the prime rib steak nice and moist.
Here’s a list of 6 other ways to Reheat Prime Rib. Pick the one that works best for you.
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Variations
Here are a few variation ideas to consider when making leftover prime patty melt sandwiches:
Mushroom Melt: Add sautéed mushrooms for an earthy, umami twist.
Onion Alternatives: In addition to, or instead of, caramelized onions, use fried onions, or Bacon Onion Jam for even more flavor and crunch.
Spicy Version: Layer in pickled jalapeños or spread chipotle mayo on the bread.
Breakfast Patty Melt: Top with a fried egg and serve with crispy hash browns.
Slider Version: Use slider rolls for party-ready bites. Check out how to make prime rib sliders.
Recipe Tips And Notes
- I highly recommend sticking to unsalted butter. Most prime rib rubs are already high in sodium.
- Low and slow is key when caramelizing onions. Rushing this step will make them bitter instead of rich and flavorful.
- If you used a crazy flavored prime rib seasoning mix, and are unsure if it will work in a patty melt, just trim off the crust of the beef before using.
- Serve immediately for the best texture. The longer it sits, the softer the bread will become.
More Leftover Prime Rib Recipes
Use leftovers to make a prime rib sandwich, prime rib breakfast casserole, prime rib quiche, prime rib soup, prime rib fried rice, prime rib tacos, and prime rib hash.
Leftover Prime Rib Patty Melt
Ingredients
CARAMELIZED ONIONS
- 2 tbsp unsalted butter
- 1 small onion, thinly sliced
- 1 tsp apple cider vinegar
PATTY MELT
- ¼ cup beef au jus, beef consommé, or beef broth (*Note 1)
- 1 slice leftover prime rib, ¼ inch – ½ inch thick (*Note 2)
- 1 tbsp unsalted butter
- 2 slices rye or marble bread
- 1-2 slices Swiss cheese
- salt, to taste (*Note 3)
Instructions
CARAMELIZED ONIONS
- Pre-heat a medium-size sauce pan over medium heat.
- Add the butter. Once melted, add the onions and toss to combine. Cover and let the onions cook, uninterrupted, for 5-6 minutes. Remove the lid, and stir for 1 minute.
- Turn the heat to low (towards the high-end of low) and stir every 6-7 minutes for 30-35 minutes, or until the onions are dark brown. Add the vinegar and use a wooden spoon to deglaze, making sure to scrap up the brown bits on the bottom of the pan. Cover and set aside.
RE-HEATING THE PRIME RIB
- Add the beef broth to a large skillet and turn the heat to medium-high. Once simmering, turn the heat to medium. Add the slice of prime rib and let cook for 1 minute per side. Remove and place on a paper towel lined plate.
MAKE THE PATTY MELT
- Use a paper towel to clean out the remaining beef broth and remnants in the skillet. Return to the heat.
- Butter the outside of the bread slices. Place one slice of bread (butter side down) in the skillet. Immediately top with the cheese, the warmed prime rib steak, caramelized onions, and the top bread slice (butter side facing out).
- Use a spatula to gently press down on the sandwich to compact all the ingredients. Cook for 2-3 minutes per side until the cheese is melted and the bread is toasted.
- Remove and serve immediately for best texture.