Preheat oven to 400°F. Gather your ingredients so that you have everything close at hand on the counter or table.
Make the Dough
You’ll want to begin by making the dough. This is easy if you use a mixer with a kneading hook. In a large mixing bowl, combine 2 1/2 cups all-purpose flour, 1 tablespoon instant yeast, 2 teaspoons granulated sugar, and 1 teaspoon kosher salt. Add in 1 cups warm water and 2 tablespoons olive oil. Mix well.
Knead by machine or by hand on a floured surface for 5-7 minutes until dough is smooth and elastic. Place dough in a greased bowl. Cover and allow to rise for 30-40 minutes.
Prepare the Ingredients
While the dough is rising, prepare the ingredients. Using a Chef’s knife and cutting board, mince 1/2 cup sweet onion. Dice 1/2 cup green bell pepper. Slice 1/2 cup black olives.
Slice 4 oz. provolone cheese, 4 oz. Swiss cheese, and 4 oz. Mozzarella cheese. Grate 2 tablespoons grated Parmesan cheese.
Prepare the white sauce by mixing together 1/4 cup real mayonnaise, 2 tablespoons Creamy Italian Dressing, 1 tablespoon minced garlic, and 1 teaspoon Italian seasoning in a small bowl.
Assemble the Stromboli
When you’re ready to assemble the stromboli, punch down the risen dough and place on a lightly floured surface. Lightly roll into a 12″ x 15″ rectangle.
Spread the creamy sauce mixture down center of dough, about 4″ wide. Sprinkle with prepared sweet onion, bell peppers, and black olives.
Layer 6 oz. Canadian bacon or ham and 6 oz. pepperoni, and then top with cheese slices.
Gently fold sides of dough up and over to lap one side over the other. Pinch seams together and fold ends of dough to seal.
Laying a piece of parchment paper next to the Stromboli, carefully turn over so seam is on the bottom, and now setting directly on the parchment paper.
Using a knife or kitchen scissors, slice breathing holes on the top.
Prepare Egg Wash and Bake
Prepare egg wash by whisking together 1 medium egg + 1 tablespoon water.
Brush egg wash over the dough and sprinkle with parmesan cheese and 1 tablespoon dried parsley.
Bake in preheated oven for 30-35 minutes until golden brown. Let stand 10 minutes before slicing. Serves 4-6.