In a large skillet over medium heat, cook the Italian sausage until browned, breaking it up with a spoon. Drain any excess fat. Remove sausage from skillet and set aside to cool slightly.

In the same skillet (or a clean one if preferred), add the diced bell pepper and onion. Sauté for 5-7 minutes until softened. Add the minced garlic and cook for another minute until fragrant. Remove from heat.

In a large mixing bowl, combine the cooled cooked sausage, diced pepperoni, diced ham, sautéed vegetables (bell pepper, onion, garlic), mozzarella cheese, provolone cheese, Parmesan cheese, dried oregano, and red pepper flakes (if using). Season with salt and black pepper to taste. Mix well to ensure all ingredients are evenly distributed.

Preheat oven to 375°F (190°C). Line a large baking sheet with parchment paper.

On a lightly floured surface, unroll the pizza dough. Using a rolling pin, roll the dough into a large rectangle, approximately 12x18 inches (30x45 cm) and about 1/4 inch thick.

Spread the prepared filling evenly over the entire surface of the rolled-out pizza dough, leaving a 1-inch border clear around the edges.

Starting from one long side, carefully roll the dough tightly into a log. Pinch the seams and ends firmly to seal the filling inside.

Carefully transfer the rolled log to the prepared baking sheet, seam-side down.

In a small bowl, whisk together the beaten egg and water to create an egg wash. Brush the top and sides of the dough log generously with the egg wash.

Sprinkle the top of the log with the remaining grated Parmesan cheese and dried Italian herbs.

Using a sharp knife, make several diagonal slits (about 1/2 inch deep) across the top of the dough, spacing them about 1-2 inches apart. Do not cut all the way through. This helps steam escape and creates a nice crust.

Bake for 35-40 minutes, or until the crust is golden brown and the cheese is melted and bubbly.

Once baked, remove from the oven and let cool on the baking sheet for 10-15 minutes before slicing and serving. This allows the filling to set and prevents it from oozing out too much.