Preheat the oven to 350°F and lightly spray a 9x11 baking dish.
Prepare the onions - In a skillet over medium heat, melt butter and sauté the sliced onions until soft and browned, about 12 minutes. Add thyme, salt, and pepper, and stir until well combined. 3 tablespoon Butter2 teaspoon Fresh Thyme¼ teaspoon salt¼ teaspoon Pepper1 Onion
Assemble the sliders - Slice the Hawaiian rolls in half (keeping them connected). Place the bottom half in the prepared baking dish. Layer with half the provolone cheese, the roast beef, the sautéed onions, and the remaining provolone cheese. Place the top half of the rolls over everything. 12 Hawaiian Slider Buns12 slices Provolone Cheese14 oz Roast Beef
Make the topping - In a small bowl, stir together the melted butter and mix in the onion soup mix. Brush evenly over the tops of the rolls. 1 Package Lipton Onion Soup Mix
Bake - Cover with foil loosely (make sure it does NOT touch the tops of the rolls). Bake for 25 minutes, until heated through, and the cheese is melted.
Prepare the gravy - While sliders bake, prepare the brown gravy according to package instructions, adding a little extra water to thin it out to your desired consistency for dipping. 1 Package Brown Gravy Mix
Serve - Slice and serve warm with brown gravy for dipping.
Video
Notes
Don't rush the onions - Let them fully caramelize for the best flavor
Use foil properly - Tent it loosely so it doesn't stick to the tops
Layer evenly - This ensures every slider has the perfect bite
Serve immediately - These are best hot and fresh out of the oven
Extra gravy is a must - The dipping makes the sandwich
Storage
Refrigeration: Store leftovers in an airtight container for up to 3 days.Freezing: You can freeze assembled (unbaked) sliders. Thaw overnight and bake as directed.Reheating: Warm in the oven at 300°F, covered with foil until heated through.