Preheat the oven to 350°F (175°C).

Without separating the rolls, slice the slider buns in half horizontally and place the bottom halves in a greased baking dish.

Layer the roast beef evenly over the bottom buns, then top with the provolone cheese. Place the top halves of the buns over the cheese.

In a small bowl, mix the melted butter, Worcestershire sauce, garlic powder, onion powder, and dried parsley. Brush or spoon the mixture evenly over the tops of the sliders.

Cover the baking dish with foil and bake for 15 minutes, or until the cheese is melted and the sliders are heated through.

Remove the foil and bake for 3 to 5 more minutes until the tops are lightly golden.

While the sliders bake, prepare the au jus by whisking the beef broth and au jus gravy mix in a small saucepan. Bring to a simmer over medium heat, then cook according to package directions until warmed through.

Serve the sliders hot with the au jus on the side for dipping.