Start by preheating your oven to 350°F (175°C). This ensures even baking right from the start. Lightly grease a 9x13-inch baking dish or line it with parchment paper to prevent sticking. This also makes cleanup easier.
Cut your slider buns in half horizontally, but don’t separate the individual rolls just yet. Place the bottom halves into the prepared dish in one solid layer, making sure they fit snugly together. This creates the base for your sliders.
Take your thinly sliced deli roast beef and spread it evenly across all the buns. Don't be afraid to stack a little; this helps create a satisfying bite. Next, lay the provolone (or Swiss) cheese slices over the beef, covering all edges so every slider gets cheesy.
Once layered, gently place the top halves of the buns back over the meat and cheese. Press them down slightly to help everything stay in place. This step makes sure the sliders hold together when sliced and served later.
In a small mixing bowl, combine melted butter, Worcestershire sauce, garlic powder, onion powder, thyme, salt, and pepper. This creates a flavorful glaze that adds texture and taste to the buns. Whisk well until everything is blended smoothly.
Using a pastry brush, generously coat the tops of the buns with the butter mixture. Try to cover the entire surface so it toasts up golden brown. You can also drizzle any leftover butter over the edges for extra richness.
Cover the baking dish tightly with aluminum foil. This traps the heat and helps melt the cheese evenly. Bake in the preheated oven for 15 minutes. Then, remove the foil and bake for another 5 minutes.
During the last 5 minutes, the tops will turn golden brown and crisp slightly while the cheese becomes perfectly melted. Once done, take the dish out and let it rest for 5 minutes before slicing.
While the sliders are baking, prepare the au jus. Pour the beef broth, soy sauce, Worcestershire sauce, garlic powder, onion powder, and pepper into a small saucepan. Stir everything together to blend the flavors.
Place the pan over medium heat and bring the mixture to a gentle simmer. Let it cook for about 5–7 minutes, stirring occasionally. Remove from heat once it’s hot and aromatic. Transfer to small bowls for dipping.
Slice the warm sliders into individual portions using a serrated knife. Carefully lift each piece out with a spatula. Arrange them on a serving tray or plate and serve immediately.
Pour the hot au jus into small dipping bowls and serve alongside the sliders. The bread soaks up the flavorful broth, making every bite juicy and delicious. Perfect for game days, parties, or easy dinners!