In a large bowl, combine the ground bison, garlic, blue cheese, onions, jalapeños, egg, salt and pepper. Roll the mixture into 12 meatballs and place them on a baking sheet.
1 ½ pounds ground bison, 2 teaspoons garlic, ½ cup blue cheese crumbles, ¼ cup red onion, 2 tablespoons pickled jalapeños, 1 large egg, 1 teaspoon salt, ½ teaspoon pepper
Bake for 30 to 40 minutes in the preheated oven, or until they reach an internal temperature of 160°F.
Meanwhile, mix all of the sauce ingredients together and reserve.
1 cup mayonnaise, 1 ½ tablespoons prepared horseradish, ⅛ teaspoon ground black pepper
Slice the slider buns in half. Place the bottom half in a 9” x 13” baking dish.
12 slider buns
Spoon a little sauce on each bun. Top with a meatball and another spoonful of sauce. Sprinkle the mozzarella cheese on top.
2 cups mozzarella cheese
Combine the butter topping ingredients together. Place the remaining half of the buns on top of the meatballs and lightly brush them with the butter topping.
2 tablespoons butter, ½ teaspoon Worcestershire sauce, ½ teaspoon onion powder, ¼ teaspoon poppy seeds, ¼ teaspoon sugar
Transfer to the oven and bake for 15 minutes, until golden and the cheese is melted.
Let cool for a few minutes and serve!
Notes
Make-ahead preparations:
The sauce and butter topping can be prepared a day or two ahead of time.
For the topping, just re-melt it before brushing it onto the sliders.
Store the slider buns in the freezer and pull them out on the day of serving to thaw so that they stay fresh.
The meatballs can be prepared and stored in the refrigerator, up to one day in advance, before baking.
Fridge storage: Leftovers can be stored in the fridge in a covered container for up to 3 to 4 days.
Reheating leftovers: You can reheat them in a 325°F to 350°F oven, covered in foil, until heated through (about 10 to 12 minutes).
Freezer storage: They can be wrapped and frozen in a freezer bag (or in a casserole dish) for up to 2 months. Make sure to label with the date. Thaw in the fridge overnight and proceed to reheat in the oven.
To avoid a soggy slider:
Oven-baking sliders helps to avoid getting them soggy.
After cooking the meat, make sure you drain the grease before building the sliders.
When it comes to reheating, use an oven rather than a microwave to retain their crispiness.
Tweaks:
To tone down the spice, you can use pickles instead of jalapeños.