Slice the rolls: Carefully slice the Hawaiian sweet rolls in half horizontally, keeping the hinged side intact so the top and bottom remain connected.
Layer the filling: On the bottom half of each roll, place one slice of Swiss cheese followed by one or two slices of ham, then top with another slice of Swiss cheese.
Make the butter mixture: In a small bowl, combine the melted butter, Dijon mustard, poppy seeds, dried minced onion, Worcestershire sauce, salt, and pepper. Stir until smooth.
Apply the topping: Brush the butter mixture generously over the top and sides of each slider.
Bake: Place the sliders on a parchment-lined baking sheet and bake at 350 degrees Fahrenheit for 15 minutes, or until the cheese is melted and the rolls are golden brown.