This 30-minute leftover roast beef sliders recipe is mouth-watering and the perfect way to use up your leftover roast beef! Piled high with tender roast beef, melty cheese, caramelized onions, and a zesty horseradish sauce, these sliders will be a hit with everyone at your next party!
🌟 Why this recipe works
The roast beef from this melt-in-your-mouth recipe is incredibly tender and flavorful.
The garlic and rosemary give it a delicious savory flavor, while the caramelized onions and horseradish sauce adds the perfect amount of sweetness and zestiness. These flavors all come together to create an absolutely fantastic slider that your guests will love!
Cooking crock pot roast beef is a budget-friendly way to get more meals from one recipe. At around $5 a pound for a rump roast or bottom round roast you can spread the cost over several meals with just one large beef roast.
Plus, these hot roast beef sliders are so easy to make! You need some cooked roast beef, swiss cheese, a 5-minute homemade zesty horseradish sauce, and some garlic butter to spread on the buns.
Homemade beef and cheese sliders are quick and easy to make in under 30 minutes, perfect for a party, BBQ, or a busy weeknight family treats for dinner.
🍽 Key Ingredients
This recipe for hot roast beef sliders uses just a few simple ingredients that you likely already have in your pantry and fridge.
Horseradish mayo - This zesty sauce is made with just 4 ingredients and takes less than 5 minutes to whip up. It's the perfect condiment for these sliders.
Roast beef - For this recipe I used the leftover of my juicy medium-rare roast beef that I made the other night. Soo good!!
Caramelized onions - These add the perfect sweetness and depth of flavor to these sliders.
Garlic butter is used to spread on the slider buns and give them a delicious flavor. If you want to make homemade garlic butter, try this easy air fried garlic bread recipe.
Dinner rolls - I used hawaiian dinner rolls for these sliders because they are so soft, buttery, and fluffy.
Cheese - I used Swiss cheese for these sliders because of the strong flavor and creamy texture. When melted, it marries well with tender beef.
Poppy seeds - I like to garnish my sliders with poppy seeds for a little extra flavor and crunch.
If you don't have Swiss cheese, you could use cheddar cheese, provolone cheese, Gruyere, or even Parmesan cheese.
Sesame seeds can be used instead of poppy seeds to add crunch.
You could also use slider buns, hamburger buns same as I use to make my Travis Scott burger copycat recipe, or even brioche buns.
🔪 How to make beef sliders
Hot roast beef sliders are an easy and fantastic way to make use of tender leftover beef and can easily be customized to make towering ones or lighter ones. Follow this easy recipe to make the best juicy slider EVER that everyone at the party will love!
Clean and peel the horseradish, then squeeze the excess moisture from it with a fine-mesh sieve or using a clean tea towel. Remove as much liquid from the horseradish as possible to prevent your mayonnaise from being watered down.
Whisk the mayo, horseradish, salt, and pepper in a medium bowl until well combined. (Tip: Add a teaspoon of Worcestershire sauce to give it a lift in flavor).
Use a serrated knife to cut the brioche buns in half on a chopping board and separate the top and bottom halves into different plates or bowls.
Chop the cooked roast beef into cubes or if you prefer you can slice it while preheating the oven to 350 degrees Fahrenheit (180 degrees Celsius).
Place the bottom buns (cut side up) into a baking dish with cooking spray on the bottom to prevent sticking. Spread the horseradish mayo onto each bun.
Distribute the sliced or chopped roast beef on top of the mayo,
Followed by the caramelized onions.
Add the swiss cheese slices on top.
Place the top buns on top, brush them with garlic melted butter,
Sprinkle the sesame seeds over.
Cover the baking dish with aluminum foil and bake the sliders for 15 minutes in the preheated oven. After 15 minutes, remove the foil and bake again for 5 minutes until the tops start to brown and the cheese is melted.
Remove the baking dish from the oven and cut out the individual sliders onto a plate ready for serving. ENJOY!
💭 Cooking tips
Extra juicy beef
If you want to make sure your beef sliders are extra juicy, try soaking the cooked roast beef in a bit of beef broth before placing them onto the sliders.
Be careful with the horseradish.
Horseradish is quite strong, so to adhere to everyone's tastes, it's better to add a tablespoon of it and taste it until you've reached your desired flavor.
Prepare them in advance.
If you want to make sliders ahead of time, you can assemble and store them in the fridge until you're ready to bake them. Just be sure to take them out of the fridge about 30 minutes before you bake them so they can come to room temperature.
📖 Recipe Variations
There are many variations of beef sliders, from adding different toppings to changing the type of bun.
Cucumber dill relish and sweetcorn relish are great options for adding a little extra sweetness and crunch to your sliders. One teaspoon is all you need to place on top of the cheese for each slider.
For a little extra spice, try adding some sliced jalapeños to your sliders. You could also use pickled jalapeños for an even more intense flavor.
Switch up the horseradish sauce
Mix 1 tablespoon of Dijon mustard and a tablespoon of honey into the horseradish mayo for a sweet and spicy kick. Another option is to mix 1 teaspoon of onion powder and garlic powder into the horseradish mayo for a more intense flavor.
Add lettuce and tomato.
If you want to add some healthy salad leaves and a few tomatoes, the best way to do so is by toasting the buns first, heating the leftover beef and caramelized onions in a skillet, and assembling everything preheated with the lettuce and tomato placed on top of the horseradish sauce.
Also check out my collection of easy leftover steak recipes when you have extra meat and dont want to waste it.
🥗 What to serve with
Sliders are usually served as a main dish or as part of a buffet. If you want to bulk them out a little, try serving them with a simple salad on the side. Try serving them with some soup or chili for a more filling meal. Here are a few tasty recipes to try.
Creamy tomato soup: This classic creamy tomato soup is the perfect comfort food and can easily be made in advance and heated up at the same time as the sliders.
Creamy mushroom: Earthy mushroom soup is a fantastic vegetarian option that's hearty and filling.
Bacon, potato, and egg salad: Made with wholesome ingredients like green onion, sweet relish, onion, garlic, cheese, hard-boiled eggs, cooked bacon, and potatoes, this salad certainly packs a punch and only takes 30-minutes to prepare.
Air fryer side dishes are the best option when you have a big crowd to feed. Check my top air fryer recipes like my crunchy air fryer tortillas chips, crispy brussel sprouts in the air fryer and my easy air fryer sweet potato cubes.
🙋 Frequently Asked Questions
How long does roast beef last in the fridge?
According to USDA standards, cooked roast beef will last 3-4 in the fridge.
What can I do with leftover beef?
There are many things you can do with leftover beef, but one of the best ways to use it is to make sliders. If you're looking to make the most out of cooked roast beef, check out these 25 leftover roast beef recipes.
Can you freeze leftover beef sliders?
Yes, you can freeze them in an airtight container. Although they taste so much better made fresh and only take 20 minutes to make, so I don't recommend freezing them.
🧊 Storing and ♨️ reheating
These roast beef sliders are perfect for making ahead or storing any leftovers in the fridge to eat hot or cold the day after.
Fridge - Cover the plate with the leftover sliders with plastic wrap or store in an airtight container for up to 2 days.
Reheating - To reheat the leftover sliders, preheat an oven to 350 degrees Fahrenheit and heat them on a baking sheet covered with aluminum foil for 10 minutes.
🍳 Related Roast Beef Recipes
If you liked this juicy leftover roast beef sliders recipe, try my featured roast recipes in your next meal.
👪 Serving size
This recipe makes 18 sliders but can easily be halved or doubled depending on how many people you're serving.
Hot roast beef sliders are a great way to use up any leftover roast beef you may have. They're easy to make and a great option for serving at a party or potluck. Whether you're looking for a tasty appetizer or a main dish, these mini sandwiches are sure to please.
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Try one of my quick, easy, and affordable dinner recipes for your next family meal! And if you have any questions, I'm here to help!
Easy Leftover Roast Beef Sliders (with Caramelized Onions)
- 18 units buns - hawaiian
- 2 pounds leftover roast beef - about 5 cups
- 1 cup caramelized onions
- 12 oz swiss cheese - slices
- 2 tablespoon garlic butter
- poppy seeds - garnish
- Clean and peel the horseradish, then squeeze the excess moisture from it with a fine-mesh sieve or using a clean tea towel. Remove as much liquid from the horseradish as possible to prevent your mayonnaise from being watered down.
- Whisk the mayo, horseradish, salt, and pepper in a medium bowl until well combined. (Tip: Add a teaspoon of Worcestershire sauce to give it a lift in flavor).
- Use a serrated knife to cut the brioche buns in half on a chopping board and separate the top and bottom halves into different plates or bowls.
- Slice or chop in cubes the cooked leftover roast beef.
- Preheat the oven to 350 degrees Fahrenheit (180 degrees Celsius).
- Place the bottom buns (cut side up) into a baking dish with cooking spray on the bottom to prevent sticking (use two baking dishes if they don't all fit into one).
- Spread the horseradish mayo onto each bun.
- Distribute the sliced or chopped roast beef on top of the mayo, followed by the caramelized onions and cheese slices.
- Place the top buns on top, brush them with garlic melted butter, and sprinkle the sesame seeds over.
- Cover the baking dish with aluminum foil and bake the sliders for 15 minutes in the preheated oven.
- After 15 minutes, remove the foil and bake again for 5 minutes until the tops start to brown and the cheese is melted.
- Remove the baking dish from the oven and cut out the individual sliders onto a plate ready for serving. ENJOY!