Preheat your oven to 425°F (220°C) and line a baking sheet with parchment paper.
In a frying pan, heat olive oil over medium heat. Add diced onion and bell pepper, and sauté for about 3-4 minutes until softened.
Increase the heat to medium-high and add thinly sliced beef sirloin to the pan. Cook for about 5-6 minutes until the meat is browned. Stir in garlic powder, Worcestershire sauce, salt, and pepper. Remove from heat and let it cool slightly.
On a floured surface, roll out the pizza dough into a large rectangle.
Spread half of the provolone cheese and half of the mozzarella cheese evenly across the dough.
Spoon the beef and vegetable mixture evenly over the cheese. Top with the remaining cheese.
Carefully fold the dough over to create a long breadstick shape. Pinch the edges to seal.
Cut the dough into individual breadsticks, about 2-3 inches wide.
Place the cut breadsticks on the prepared baking sheet and brush the top with the beaten egg for a golden finish.
Bake in the preheated oven for 12-15 minutes, or until golden brown and bubbly.
Remove from the oven and let cool for a few minutes. If desired, sprinkle with dried parsley before serving.