The recipe also takes just a few minutes to prepare, so it takes about 30 minutes before dinner is ready to serve and on busy weeknights, fast prep meals can be a lifesaver.
Preheat the oven to 350 degrees F.
Spray the bottom of a 9 x 13 baking dish.
Do not separate the rolls into individual rolls. Take the entire block of 12 rolls and slice through the rolls creating a top section and a bottom section.
Place the bottom half of the rolls in the baking dish.
Top with 6 slices of the provolone cheese, roast beef, french fried onions, remaining 6 slices of cheese, and the other half of the rolls, in that order.
In a small bowl, melt the butter in the microwave.
Mix in 1 tablespoon of the au jus seasoning mix, Worcestershire sauce, sesame seeds, dried minced garlic, onion powder, and whisk until well combined.
Top the rolls evenly with this mixture. Top until well coated. You may have some leftover that you can set aside and use to dip the sandwiches in while eating if you want.
Bake uncovered for 12- 15 minutes until the cheese is melted and the tops of the rolls are golden brown.
Remove and cut the sliders into 12 separate slider sandwiches and serve immediately.
While the sliders are baking, take the remaining au jus mixture and place in a small saucepan over medium heat. Add 2 cups cold water and whisk. Bring to a boil and then reduce the heat to a simmer to allow it to slightly thicken.
Serve with the sandwiches.