Soft tops, crisp bottoms, melty warm middle. These ham and cheese sliders are brushed with seasoned butter and baked on a sheet pan or baking dish. Fast to assemble, easy to refill, and always the first tray gone.
Preheat oven to 350 degrees F. Lightly grease a 9x13-inch baking dish.
In a small bowl, mix together melted butter, Dijon mustard, Worcestershire sauce, poppy seeds, and dried onion.
Slice the slider buns horizontally. Place the bottom half into the prepared baking dish. Layer about half the ham onto the rolls. Arrange the Swiss cheese over the ham, and top with remaining ham slices in a layer. Place the tops of the rolls onto the sandwiches. Pour the mustard mixture evenly over the rolls.
Bake until the rolls are lightly browned and the cheese has melted, about 20 minutes. Slice the sliders to make individual sandwiches.