01 -
Melt 2 tablespoons butter in a skillet over medium heat. Add chopped onions and cook until softened, about 4 minutes. Stir in minced garlic and cook for an additional 2 minutes, then remove from heat.
02 -
Preheat oven to 350°F. Using a long serrated knife, carefully slice the slider rolls in half horizontally. Arrange the bottom halves in a foil-lined 9x13-inch baking dish or on a baking sheet lined with non-stick liner.
03 -
In a small bowl, combine mayonnaise and horseradish until smooth. Spread this mixture evenly over the bottom halves of the rolls.
04 -
Place half of the roast beef slices over the mayo-covered rolls, folding slices to fit evenly. Top the meat with half of the provolone cheese slices. Repeat with remaining roast beef and cheese layers.
05 -
Distribute the warm sautéed onions and garlic evenly over the top layer of cheese.
06 -
Place the top halves of the slider rolls on each assembled sandwich to create sliders.
07 -
Melt 5 tablespoons butter and stir in Worcestershire sauce, Dijon mustard, and poppy seeds. Using a basting brush or spoon, evenly coat the top of the sliders with the glaze.
08 -
Bake in the preheated oven for 10 to 15 minutes, or until the sliders are warmed through and cheese is melted.