Melt 2 tablespoons of Chef Shamy French Onion Butter in a large skillet over medium heat. Add  the onions and reduce the heat to medium low. Cook, stirring occasionally, until lightly caramelized (softened and browned), about 25-30 minutes. *Tip-If the onions start to become dry or burnt, add a little bit 1-2 tablespoons of water to the skillet - I had to do this twice. You can also try turning down the heat a bit.

Preheat oven to 350 degrees.

Thinly slice the roast beef into strips and add them to the skillet. Stir in the beef broth and Worcestershire sauce. Bring to a simmer over medium heat and cook for 5 minutes. Drain off any excess liquid (you don't want it soaking into the slider buns and making them mushy).

Separate the buns in half so you have a “slab” of tops and a “slab” of bottoms; don't pull the rolls apart and slice individually because you want to keep them connected. Lay the bottom buns out in a 13x9-inch baking dish.

Using a slotted spoon to drain any excess liquid, evenly arrange the meat mixture over the bottom buns. Sprinkle the shredded Asiago cheese evenly over the meat. Cover with the top slab of buns.

Brush the tops of the slider buns with the melted French Onion Butter. Sprinkle on 1 tablespoon of finely shredded Asiago cheese and chopped parsley.

Bake in the preheated oven for 20 minutes, or until cheese is melted and tops are lightly browned.