2/3 c. (about 4 oz.) Treasure Cave® Crumbled Blue Cheese, plus additional for serving
Zest of 1 lemon, plus 1 tbsp. fresh lemon juice
Freshly ground black pepper
6 pieces (about 6 oz.) thick-cut bacon
1 large yellow or white onion, peeled and thinly sliced
1/3 c. bourbon
Extra-virgin olive oil
12 brioche slider buns
Unsalted butter, for toasting buns
12 large basil leaves
Place steak on a plate and season generously on all sides with salt. Some salt will come off when you pat the steak dry later, so don’t be shy–season with gusto. Let steak come to room temperature as you prepare components for sliders.
In a medium bowl, combine mayonnaise, ⅔ cup Treasure Cave® Crumbled Blue Cheese, lemon zest, and lemon juice. Stir to combine and season with salt and pepper. Transfer to refrigerator until ready to serve.
Place a large cast iron skillet over medium-high heat. Add bacon and cook, flipping occasionally, until slices are crisp and golden, about 12 to 15 minutes. Transfer to a paper towel-lined plate to drain.
Remove all but 2 tablespoons bacon fat from pan, reserving any remaining fat for searing steak. Add onions, season with salt and pepper, and cook, stirring occasionally, until golden on the edges and starting to caramelize, about 12 to 15 minutes. Reduce heat if necessary to prevent burning. Add bourbon and stir to deglaze bottom of pan until nearly evaporated, about 30 seconds. Transfer onions to a bowl until ready to assemble sliders.
Wipe out skillet and place over medium-high heat. Add 2 tablespoons reserved bacon fat, using olive oil as necessary if not enough bacon fat remains. When fat just begins to smoke, add steak. Sear until well caramelized and crusty on the underside, about 6 to 8 minutes. Flip, and continue cooking until steak is golden, about 4 to 6 minutes more; an instant-read thermometer stuck into the middle of steak should read 125° to 130° for medium-rare. Using a pair of tongs, hold one side of steak to the surface of the skillet, rolling back and forth as necessary to brown, about 1 ½ minutes. Repeat with the second side of steak.
Remove steak to a rack and let rest to allow juices to redistribute, 10 minutes. (If you prefer your steak room temperature, let rest up to 30 minutes.) Thinly slice against the grain. Taste a slice and season to taste with additional salt and pepper if necessary.
As steak rests, toast slider buns: Split buns in half. Place cast iron skillet back on the burner over medium-high heat. Add 1 tablespoon butter. When melted, add as many buns will fit, cut sides down. Toast until lightly golden, about 1 to 2 minutes. Repeat with remaining buns, replenishing butter as necessary between batches.
Assemble sliders: Spread blue cheese mixture on both sides of the slider buns. Add a basil leaf to the bottom halves of the buns. Break the bacon slices in half and divide among the buns, along with the steak, caramelized onions, and additional Treasure Cave® Crumbled Blue Cheese. Using toothpicks, finish each slider with a bun top and serve.