Preheat oven to 350°F (175°C).
Slice slider buns in half and place the bottom halves in a baking dish.
Spread shredded pot roast evenly over the buns.
Add sliced pepperoncini peppers over the meat.
Lay cheese slices over the filling.
Place the top halves of the buns over the cheese.
In a bowl mix melted butter, garlic powder, Worcestershire sauce, and parsley.
Brush the butter mixture over the tops of the buns.
Cover with foil and bake for 15 minutes.
Remove foil and bake another 5 minutes until the tops are golden.