01 -
In a large skillet over medium heat, melt 3 tablespoons unsalted butter. Add the sliced onion and cook, stirring occasionally, for 12-15 minutes until soft and browned without burning.
02 -
Stir in minced thyme, kosher salt, and black pepper into the onions. Remove from heat.
03 -
Preheat oven to 350°F. Slice the Hawaiian rolls horizontally, keeping them intact. Place the bottom halves, cut side up, into an 11×7-inch or 9×13-inch baking dish.
04 -
Layer half of the provolone slices over the bottom rolls, then evenly top with the deli roast beef and the caramelized onions.
05 -
Place the remaining provolone cheese over the onions, then cover with the top halves of the rolls.
06 -
In a small bowl, combine melted unsalted butter and dried onion soup mix. Brush this mixture evenly over the top rolls.
07 -
Cover the baking dish loosely with foil, ensuring it does not touch the rolls. Bake for 25 minutes, then remove the foil and bake an additional 5 minutes to brown the top.
08 -
While baking, prepare the au jus by following the packet instructions using 3 cups of water.
09 -
Serve the sliders garnished with fresh parsley alongside the au jus for dipping.