1tablespoonneutral oil (like canola, grapeseed, or peanut oil)
1tablespoonunsalted butter
2largeyellow onionshalved and sliced paper thin
2teaspoonskosher saltplus more for seasoning onions and mushrooms
1ouncerye or whiskey
For The Sauteed Mushrooms:
1tablespoonneutral oil (like canola, grapeseed, or peanut oil)
1tablespoonunsalted butter
2mediumgarlic cloves
3sprigsfresh thyme
12ouncescremini mushroomsstemmed and thinly sliced
kosher salt
Freshly ground black pepper
For The Burgers:
1poundground bison
8slicesSwiss cheese
For Serving:
8mini burger buns
Good-quality mayonnaisefor serving
2handfulsbaby arugulafor serving
Instructions
Make The Caramelized Onions: Heat 1 tablespoon of each the oil and butter in a medium cast iron pan (or other heavy-bottomed pan) over medium-high heat. Add the onions and a pinch of salt and stir to coat. Reduce the heat to low and cook, stirring every few minutes, until the onions are softened and golden brown, at least 20 minutes. Remove the pan from the stove, add the whiskey, stir to coat and return to the stove over medium heat. Cook just until the alcohol smell is cooked off then set aside until ready to use. Meanwhile, make the mushrooms.TIP: Onions can be caramelized up to four days in advance. Store refrigerated in an airtight container and warm up when ready to use.
Brown The Mushrooms: Heat 1 tablespoon of each the oil and butter in a medium cast iron pan (or other heavy-bottomed pan) over medium-high heat. When the oil shimmers, add the mushrooms, thyme, and garlic, stir to coat in the oil, season with salt and pepper and cook undisturbed at least 5 minutes. Stir the mushrooms occasionally and continue to cook until the mushrooms have let off the excess water and they're golden brown, about 5 to 10 minutes more. Remove from heat, add thyme leaves, and set aside until ready to use.TIP: Mushrooms can be caramelized up to four days in advance. Store refrigerated in an airtight container and warm up when ready to use.
Cook The Bison Burgers: Heat the grill or grill pan to medium heat (350°F) and rub the grate with a towel dipped in oil. Shape ground bison meat into 8 (1/4-inch thick) patties and brush the patties with vegetable oil. Cook the patties until browned on first side, about 1 to 2 minutes. Flip, add a slice of cheese to each slider, close grill top and cook until cheese is melted and patty is cooked through, about 1 to 2 more minutes.
Serve The Bison Burgers: Serve the sliders on the buns topped with mayonnaise, mushrooms, onions, and arugula.