In a small bowl, mix together melted butter, Worcestershire, garlic and onion powder, and parsley. Set aside.
Season the shaved steak meat with kosher salt and pepper. Set aside.
With a serrated knife, cut the rolls in half and set aside the tops. Place the bottoms in a parchment-lined casserole dish. Spread some of the melted butter mixture evenly on the bottom half of the rolls, reserving most for later on top.
In a large skillet over medium-high heat, add half the oil and add the steak. Using tongs, toss the steak, working quickly until the desired doneness is achieved. The steak should be well done. Remove from the skillet and set aside.
Heat the remaining oil and add the onions and green peppers. Season with salt and pepper and cook over medium heat until peppers are soft and onions are caramelized slightly.
Add back in the steak, pour in the Worcestershire sauce garlic powder, and onion powder, and toss to coat. The transfer the mixture over top of the bottoms of the rolls.
Add a layer of provolone cheese. Add the top half of the buns back and pour the rest of the butter mixture slowly overtop to coat. Use a brush to get between the rolls and the sides.
Cover the top of the casserole dish with aluminum foil to prevent the sliders from browning too quickly. Bake for 20 minutes. Remove foil and bake for additional 10-15 minutes until golden brown.
Store leftovers in an airtight container in the fridge for up to 2-3 days.