Preheat your oven to 400°F (200°C).
Roll out the pizza dough on a floured surface into a large rectangle.
Spread Dijon mustard evenly over the rolled-out dough.
Layer the ham and Swiss cheese evenly over the mustard.
Sprinkle garlic powder, oregano, salt, and pepper over the ham and cheese.
Carefully roll the dough tightly away from you, pinching the ends to seal.
Place the rolled stromboli seam-side down on a baking sheet lined with parchment paper.
Brush the top with the beaten egg for a shiny finish.
Using a sharp knife, make a few slashes on top of the stromboli to allow steam to escape.
Bake for 20-25 minutes or until golden brown.
Allow to cool slightly before slicing and serving with your favorite dipping sauce.