PREP: Preheat oven to 350°F (175°C). Generously grease a 9x13-inch baking pan. Line pan with parchment paper.
BUTTER: In a microwave-safe bowl, melt the butter and let it cool slightly. Whisk in remaining ingredients listed under "butter."
BRUSH ON BUTTER: Using a serrated bread knife, carefully slice the entire block of Hawaiian rolls in half horizontally, keeping the individual rolls attached (See Note 1). Place the bottom half of the rolls in the prepared pan.Brush 2 tbsp of the butter mixture on the cut sides of both the top and bottom halves of the rolls (using 4 tablespoons in total).
LAYER IN FOLLOWING ORDER: 6 slices of cheese, roast beef, well-drained peperoncinis (if using), 6 remaining slices of cheese. Do not add top slab of rolls yet. Bake, uncovered, for 10 minutes.
BAKE AGAIN: Remove pan from oven and place top half of the rolls onto the sliders. Generously brush the top and sides with the remaining butter mixture. Optionally, sprinkle with grated Parmesan cheese. Cover the pan with foil and bake for 20 minutes. Remove the foil and bake for an additional 10 minutes or until the top is golden brown and the cheese is melted.
ENJOY: Serve hot, cutting into individual sliders.
Video
Notes
Note 1: Rolls: Keep the rolls intact and slice them in half horizontally.Note 2: Beef: Choose the rarest deli roast beef to avoid overcooking in the oven. Simply ask the deli counter staff for assistance.Note 3: Peperoncini: If you're not a fan, feel free to omit them or replace with banana peppers for less heat. Thoroughly drain and squeeze out extra moisture with a paper towel. Ensure they're very dry before adding to sliders.