Heat olive oil in a skillet over medium heat. Add onion and roasted red peppers; cook and stir until onions are tender, about 5 minutes. Add garlic; cook and stir until fragrant, about 1 minute. Add spinach and basil; cook and stir until spinach is wilted, about 3 minutes.
Stir in ham, sausage, mozzarella cheese, and Cheddar cheese until evenly combined.
Roll pizza dough into a 12x14-inch rectangle. Spread ham and cheese mixture down the center of the dough. Fold the dough over the filling, pressing the edges together to seal. Place stromboli on a baking sheet.
Brush beaten egg over the top of the dough. Bake in preheated oven until golden brown, about 25 minutes.
Allow to cool for 5 minutes before slicing and serving.
Interesting Facts
Stromboli originated in Italy as a way of using up leftovers.
Stromboli is similar to a calzone, but the dough is shaped differently.
This dish can be frozen and reheated for a quick meal.
You can use any combination of meats and cheeses for this recipe.