Preheat your oven to 350°F (175°C) and grease a baking dish generously.

Carefully slice the slider rolls in half and spread a layer of Dijon mustard on both cut sides.

Place a generous layer of sliced ham on the bottom half of the rolls, then add an even layer of cheese.

In a small bowl, combine the melted butter with poppy seeds. Brush it over the assembled sliders.

Cover the baking dish with foil and bake for 15 minutes, then uncover and bake for an additional 10 minutes.

Let the sliders cool slightly before slicing into individual servings.