Cut and separate the tops of the rolls from the bottoms. Place the bottom rolls in a sheet pan or casserole dish.
Layer mustard, pulled pork, ham slices, cheese and pickles on the sliders. Cover with the tops of the rolls.
In small bowl, add butter, onion, dry mustard, Worcestershire, and garlic powder. Heat mixture in microwave about 20-30 seconds on high or until melted. Stir until combined.
Brush tops of rolls with butter mixture. Cover sliders with foil.
Bake for 10 minutes covered. Uncover and back for about 10-15 minutes longer, or until cheese is melted and tops of rolls are golden brown.
Top each slider with toothpick holding 1-2 pieces of dill pickle popcorn.