01 -
Melt 2 tablespoons butter in a skillet over medium heat. Add chopped onions and cook until soft and translucent, about 5 minutes. Stir in minced garlic in the last 2 minutes and cook until fragrant. Remove from heat and set aside.
02 -
Preheat oven to 350°F. Use a serrated knife to slice Hawaiian rolls horizontally in half. Arrange the bottom halves in a foil-lined 9x13-inch baking dish or on a baking sheet lined with non-stick paper.
03 -
Combine mayonnaise and horseradish in a small bowl until smooth. Spread this sauce evenly over the bottom halves of the slider rolls.
04 -
Layer half of the roast beef slices over the sauce, folding the meat for even coverage. Top with half of the provolone slices. Repeat with the remaining roast beef and provolone to create two meat and cheese layers.
05 -
Evenly distribute the warm sautéed onions and garlic over the top layer of cheese. Place the top halves of the rolls onto the sliders to close the sandwiches.
06 -
In a small bowl, combine 5 tablespoons melted butter, Worcestershire sauce, Dijon mustard, and poppy seeds. Brush or spoon the glaze evenly over the tops of the assembled sliders.
07 -
Bake in the preheated oven for 10 to 15 minutes until the sliders are heated through and the cheese is melted. Remove from oven and serve warm.