Preheat your grill to 350° F for indirect cooking.
Prep the rolls. Using a large bread knife, slice the rolls in half, separating the tops from the bottoms. Tear off a large piece of Reynolds Wrap® Non-Stick Foil and place the bottom section of the rolls on the foil. Set aside the tops of the rolls.
Make the sandwiches. Spread the cut side of the bottom rolls with whole-grain mustard. Top with folded pieces of the sliced ham and a single layer of sliced cheese. Place the tops of the buns back onto the sandwiches.
Top with honey butter and poppy seeds. Melt your butter in a small bowl and stir in the hot honey. Brush the tops of the sliders with the honey butter, letting the butter drip down the sides and into the cracks of the rolls. Sprinkle the tops of the rolls with the poppy seeds.
Cook. Fold the long edges of the foil up and around the rolls, crimping the edges to make a foil pack. Place the wrapped rolls on the indirect heat side of the grill and close the lid. Let the sliders cook for 20 minutes.