Prepare the Steak Filling
Heat olive oil in a skillet over medium-high heat.
Add the thinly sliced steak, Worcestershire sauce, garlic powder, salt, and pepper.
Cook for 3-5 minutes until browned, then remove from heat.
Caramelize the Onions
In the same skillet, melt butter and add sliced onions.
Cook over medium-low heat, stirring occasionally, until onions are soft and golden brown (about 10-12 minutes).
Assemble the Sliders
Preheat oven to 350°F (175°C).
Slice the slider buns in half and place the bottom halves in a greased baking dish.
Layer the cooked steak evenly over the buns, followed by the caramelized onions.
Place provolone cheese slices on top and cover with the top half of the buns.
Add the Buttery Topping
Mix melted butter with garlic powder and brush over the tops of the buns.
Sprinkle with sesame seeds for extra flavor.
Bake and Serve
Cover with foil and bake for 10 minutes, then remove foil and bake for another 5 minutes until golden brown and cheese is fully melted.
Garnish with chopped parsley, serve warm, and enjoy!