Preheat your oven to 350°F (175°C).
In a saucepan, whisk together the beef broth, water, Worcestershire sauce, garlic powder, and onion powder. Bring to a simmer over medium heat.
1 (10.75 ounce) can condensed beef broth, 1 cup water, 1 tablespoon Worcestershire sauce, 1 teaspoon garlic powder, 1/2 teaspoon onion powder
Slice the slider buns in half horizontally. Place the bottom halves in a baking dish.
12 slider buns
Evenly distribute the sliced roast beef over the bottom buns.
1.5 lbs cooked roast beef
Top the beef with slices of provolone cheese.
4 ounces provolone cheese
Place the top halves of the slider buns over the cheese.
12 slider buns
If desired, brush the tops of the slider buns with melted butter.
2 tablespoons butter
Cover the baking dish with foil and bake for 15 minutes. Remove the foil and bake for an additional 5-10 minutes, or until the cheese is melted and the buns are lightly golden.
Slice the sliders apart and serve immediately with the warm au jus for dipping.
