Prepare the Sliders:

Preheat Oven: Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking dish or line it with parchment paper.

Assemble the Sliders: Slice the slider buns in half horizontally, keeping the bottoms and tops connected. Place the bottom half of the buns in the prepared baking dish.

Layer Ingredients: Layer the roast beef evenly over the bottom buns, followed by the provolone cheese. Place the top half of the buns over the cheese.

Make the Butter Mixture:

Mix Butter Sauce: In a small bowl, combine the melted butter, Dijon mustard, Worcestershire sauce, garlic powder, and onion powder. Stir well.

Brush the Buns: Use a pastry brush to generously coat the tops of the buns with the butter mixture. Sprinkle with dried parsley if desired.

Bake the Sliders:

Bake: Cover the baking dish with foil and bake for 15 minutes. Remove the foil and bake for an additional 5 minutes, or until the tops are golden brown and the cheese is melted.

Prepare the Au Jus:

Make Au Jus: While the sliders bake, prepare the au jus according to the package instructions using the water. Heat it in a saucepan over medium heat until hot.

Serve:

Serve: Remove the sliders from the oven and cut them into individual portions. Serve warm with the au jus for dipping.