Preheat your oven to 400°F (200°C).

Roll out your pizza dough into a rectangle about 1/4 inch thick.

Spread a layer of marinara sauce over the dough, leaving a 1-inch border around the edges.

In a mixing bowl, combine mozzarella, provolone, bell peppers, mushrooms, red onion, and black olives. Add Italian seasoning, mix well.

Distribute the cheese and veggie mixture over the marinara sauce, maintaining a 1-inch border.

Roll the dough tightly from one side to the other, sealing in the filling by pinching the edges.

Place the rolled Stromboli seam side down on a lined baking sheet. Brush with beaten egg.

Slice a few slits in the top of the Stromboli to allow steam to escape.

Bake for 20-25 minutes or until the crust is golden brown.

Let it cool for a few minutes, slice, and serve warm with extra marinara sauce.