Step 1: Preheat the Oven
Preheat your oven to 350°F (175°C) and grease a 9×13-inch baking dish.
Step 2: Assemble the Sliders
- Slice the slider buns in half, keeping them connected as a sheet if possible.
- Place the bottom halves of the buns in the prepared baking dish.
- Layer with half of the cheese slices, then the roast beef, and finally the remaining cheese.
- Place the top halves of the buns over the filling.
Step 3: Make the Butter Topping
- In a small bowl, whisk together the melted butter, Worcestershire sauce, garlic powder, onion powder, Dijon mustard, parsley, salt, and black pepper.
- Brush the butter mixture evenly over the top of the sliders.
Step 4: Bake the Sliders
- Cover the dish with foil and bake for 15 minutes.
- Remove the foil and bake for another 5-7 minutes, until the tops are golden brown and the cheese is melted.
Step 5: Prepare the Au Jus Dipping Sauce
- In a small saucepan, combine beef broth, Worcestershire sauce, garlic powder, onion powder, and black pepper.
- Bring to a simmer over medium heat and let cook for 3-4 minutes.
- If desired, mix 1 teaspoon cornstarch with 1 tablespoon water and stir it into the sauce to thicken.
- Remove from heat and transfer to small bowls for dipping.
Step 6: Serve and Enjoy!
- Remove sliders from the oven and let them rest for 5 minutes before cutting.
- Serve warm with au jus sauce on the side for dipping.