This 30-minute leftover roast beef slidersrecipe 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!
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).
Cooking
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!
Recipe Notes
Extra juicy beefIf 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 potent, 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.