Preheat the oven to 425°F. Line a standard sheet pan with parchment paper or a silpat.
In a skillet, saute the onion and bell pepper in a couple of drizzles of olive oil. Season with 1 tsp of dry Italian seasoning, garlic salt and black pepper to your taste. Saute for 3-5 minutes until softened.
Press the pizza dough into roughly a 16x12-inch rectangle. Top with half of the shredded cheese.
Arrange the chopped steak over the cheese and top with the cooked onion and pepper.
Drizzle with ⅓ cup Parmesan-Peppercorn dressing, then top with the remaining shredded cheese.
Begin rolling starting with the widest edge ending seam side down. Transfer to sheet pan seam side down on the parchment paper.
Brush the top and sides with melted butter. Season the top with ½ tsp dry Italian seasoning and garlic salt to your taste. Sprinkle with 2 Tbsp grated Parmesan cheese.
Place into the oven and bake for 18-20 minutes until golden brown.
Let stand on the counter for 5 minutes then slice and serve.
Notes
Protein - This cheesesteak stromboli is made with grilled steak. You could use grilled chicken instead.
Don't Overcook the Steak - It's important that the steak not be overcooked initially, or it could be dry once the stromboli is assembled and baked in the pizza dough. It should also be cool.
Dressing - If you're unable to find Parmesan peppercorn salad dressing you can use a bottled Caesar dressing, creamy Italian dressing or any similar dressing with the same flavor profile.
DIY Parmesan-Peppercorn Ranch Dressing - Mix 1/3 cup classic Ranch dressing with 2 tablespoons grated Parmesan cheese and 1/2 teaspoon freshly ground black pepper.
Egg - You could brush the dough with an egg wash in place of melted butter prior to baking.