Heat the Oven: Start by preheating your oven to 350°F. Lightly grease a baking dish so the sliders do not stick and clean up stays easy.
Slice the Rolls: Keep the rolls connected and slice them horizontally as one slab. Place the bottom half into the baking dish, keeping them snug.
Layer the Filling: Lay the ham evenly over the bottom rolls, folding pieces slightly for texture. Add the Swiss cheese on top, covering the ham completely.
Add the Top Rolls: Place the top half of the rolls over the cheese. Press gently so everything settles together.
Mix the Butter Sauce: In a small bowl, stir together melted butter, Dijon mustard, Worcestershire sauce, garlic powder, poppy seeds, chives, salt, and pepper until smooth.
Pour and Rest: Slowly pour the butter mixture over the rolls, making sure it seeps into the cracks. Let the sliders rest for about 10 minutes so the flavor sinks in.
Bake Until Golden: Cover loosely with foil and bake for 15 minutes. Remove foil and bake another 10 minutes until the tops turn golden and the cheese melts fully.