Step 1: Prep the Rolls

Slice the rolls horizontally into tops and bottoms using a serrated knife. Place the halves, cut side up, on a baking sheet.

Preheat the broiler and toast the rolls for 1–2 minutes until lightly golden. Keep an eye on them to prevent burning.

Step 2: Assemble the Sliders

Preheat the oven to 350°F (175°C). Lightly grease a ceramic or glass baking dish.

Lay the bottom halves of the toasted rolls in the dish, cut side up.

Mix mayonnaise and cream-style horseradish in a small bowl. Spread half of this mixture over the bottom rolls.

Layer half of the cheese slices, followed by all the roast beef, caramelized onions, and the remaining cheese. Spread the rest of the mayo-horseradish mixture on the cut side of the top rolls and place them over the filling.

In a small bowl, combine melted butter, Worcestershire sauce, garlic powder, onion powder, and parsley. Brush this mixture generously over the tops and sides of the rolls.

Step 3: Bake the Sliders

Cover the baking dish with foil and bake for 20 minutes until heated through and the cheese is melted.

Remove the foil and bake for another 5–8 minutes until the tops of the rolls are golden and slightly crisp.

Let the sliders rest for a couple of minutes before slicing them into individual portions with a serrated knife. Garnish with additional parsley if desired.

Step 4: Make the Jus

While the sliders bake, melt butter in a saucepan over medium heat. Add garlic and cook until fragrant, about 1–2 minutes.

Stir in the flour and cook for another 1–2 minutes.

Gradually whisk in beef broth, Worcestershire sauce, thyme, and black pepper. Bring the mixture to a boil, then reduce heat and let it simmer for 10 minutes, stirring occasionally.

Taste and adjust seasoning with bouillon base, salt, and pepper as needed. Strain through a fine mesh sieve to remove solids.

Step 5: Serve

Serve the sliders warm with the jus in small cups for dipping. Enjoy the combination of gooey cheese, tender roast beef, and the flavorful jus!