01 - Set oven to 350°F (175°C) and allow to fully preheat while preparing other elements.
02 - In a large skillet over medium heat, combine 1 tablespoon olive oil and 1 tablespoon unsalted butter. Add sliced onions, green bell pepper, and red bell pepper. Sauté for 5 to 7 minutes until vegetables become tender. Stir in minced garlic and cook for an additional minute. Transfer vegetables to a bowl and set aside.
03 - Return the skillet to medium-high heat. Add sliced steak, seasoning evenly with salt, black pepper, and Worcestershire sauce if using. Cook for 3 to 4 minutes, stirring to ensure even browning. Reintroduce the reserved vegetable mixture and toss to evenly combine.
04 - Slice slider buns horizontally, keeping the tops and bottoms attached. Arrange the bottom halves in a greased baking dish.
05 - Spread the steak and vegetable mixture evenly over the bun bases. Lay provolone cheese slices over the filling, ensuring full coverage. Place the top halves of the buns onto the cheese.
06 - Melt the remaining 2 tablespoons unsalted butter. Brush onto the tops of the buns using a pastry brush. If desired, sprinkle with sesame seeds for additional flavor and texture.
07 - Cover the dish with aluminum foil and bake for 10 minutes. Remove foil and continue baking for an additional 5 minutes, until cheese has fully melted and bun tops are golden.
08 - Remove from oven and allow to cool for several minutes. Slice the sliders and serve while warm.