Instructions:

1. Preheat your oven to 200°C (400°F) and line a baking sheet with parchment paper.
2. In a large skillet, heat olive oil over medium-high heat. Add the sliced steak and cook for 3-4 minutes, until browned. Remove from the skillet and set aside.
3. In the same skillet, add the sliced onion, bell pepper, and mushrooms (if using). Cook for 5-7 minutes until softened. Season with salt, pepper, and Worcestershire sauce. Remove from heat.
4. On a floured surface, roll out the pizza dough into a large rectangle, about 10×14 inches.
5. Spread the cooked steak evenly down the center of the dough, leaving a 1-inch border on all sides. Add the cooked veggies on top of the steak. Sprinkle the shredded cheese over the top.
6. Fold the sides of the dough over the filling, then fold the top and bottom edges over to seal the stromboli. Carefully transfer it to the prepared baking sheet, seam-side down.
7. Brush the top of the stromboli with the beaten egg for a golden, shiny finish. Sprinkle with sesame seeds if desired.
8. Bake for 20-25 minutes, until golden brown and the cheese is melted and bubbly.
9. Let the stromboli cool for 5 minutes before slicing. Serve with marinara sauce or cheese sauce for dipping.