2poundscooked roast beef, shredded or roughly chopped (about 5.5 to 6 cups)
1 to 1.5cupscaramelized onions(depending on how much onion flavour you want. You can use fried onions, if you like)
320gramsSwiss cheese, shredded (or about 12 ounces or 3.5 to 4 cups or use 12 slices)
2 to 3tablespoonsgarlic butter, melted
6 to 8tablespoonshorseradish, squeezed of excess moisture (use less if you want less of a horseradish flavour)
Carefully cut buns in a half (horizontally so you have a bottom portion and top portion (and leave individual buns intact)). Preheat oven to 350 degrees Fahrenheit.Note: This recipe makes about 18 to 24 sliders (depending on how much toppings you want on them). Also, if you pile on less (or more) toppings onto your buns, the quantity you yield may vary. You can easily half the recipe if you like.
Spread horseradish mayo over insides of buns. Place bottom buns in a baking dish (use two baking dishes if needed (one for each set of 12 buns)).
Distribute beef over buns. Top with caramelized onions and cheese. Then, place top buns over top.
Cover with foil and bake in preheated oven for 15 minutes. Carefully remove foil and bake another 5 minutes or so or until cheese is melted and sliders are heated through.
Squeeze excess moisture from horseradish via a sieve or using a clean tea towel. This helps prevent your mayo from being watered down.
Then, combine all ingredients in a bowl, stirring well to combine. Note: Add a tablespoon or so of horseradish at a time until you've reached your desired flavour.
Prep time does not include caramelizing onions. If you are including those and do not already have on hand, they take about 60 minutes to prepare.
Don't have garlic butter on hand? Infuse some butter with minced garlic and heat up to get that garlic goin'. Not a fan of garlic? Use regular ol' butter!
Swiss cheese was used here, but you could use your favourite melty cheese. Cheddar, mozzarella or gouda would also be delicious options.
Don't have caramelized onions on hand or don't have time to make them? Try fried onions instead. They're quicker to prepare and you'll still get an onion flavour!
Add some texture! Sprinkle some sesame seeds or poppy seeds onto those buttered buns before baking.
If you have leftover au jus from your roast beef dinner, warm that up and serve alongside so they're like french dip sliders!
These are beef sliders for a crowd (hello weekend get together), but you could easily half the recipe if you prefer.