Horizontally slice Hawaiian rolls in half and place the bottom half in pan.
Layer with 6 slices cheese, roast beef, French fried onions, and remaining cheese. Top with the other half of the rolls.
For the seasoning, melt butter in microwave. Stir in ½ package of au jus seasoning mix, Worcestershire sauce, onion powder and seasoned salt.
Top the rolls with this mixture, making sure all the rolls are entirely coated.
Bake the sliders uncovered until the tops of the rolls are golden brown, about 15-20 minutes.
While the sliders are baking, take the remaining packet of au jus and place in a small saucepan over medium heat. Add 2 cups water and whisk. Bring to a boil and then reduce the heat to a simmer and allow it to thicken.