- In a large skillet over medium heat, melt the butter.
- Add the onions and cook, stirring occasionally, for about 12-15 minutes until soft and browned.
- Stir in the thyme, salt, and pepper. Remove from heat and set aside.
- Preheat the oven to 350°F.
- Slice the sweet rolls across so you have the tops and bottoms separated.
- Place the bottom halves of the rolls in an 11×7 baking dish.
- Top with half of the provolone cheese.
- Layer the roast beef over the cheese.
- Spread the caramelized onions evenly over the roast beef.
- Add the remaining provolone cheese and place the top halves of the rolls on top.
- In a small bowl, stir together the melted butter and dried onion soup mix.
- Brush the butter mixture evenly on top of the rolls or pour it over them.
- Cover the baking dish loosely with foil and bake for 25 minutes.
- Remove the foil and bake for an additional 5 minutes to brown the rolls.
- While the sliders are baking, prepare the au jus gravy mix per the package directions using water.
- Serve the sliders with a garnish of fresh chopped parsley, if desired, and au jus on the side for dipping.
Now, sit back, relax, and enjoy these delicious French Dip Sliders. Take a bite and savor every moment of this crowd-pleasing comfort food.
