Preheat your oven according to the instructions on the gluten-free pizza crust box.
Spread the shredded mozzarella cheese evenly over the pizza crust.
Bake the pizza for the recommended time on the box, or until the cheese is melted and golden brown.
While the pizza is baking, prepare the chopped toppings. On a cutting board, chop the romaine lettuce, salami, turkey pepperoni, and banana peppers into bite-sized pieces. Add the chopped red onion.
In a small bowl, whisk together the olive oil, red wine vinegar, and Italian seasoning.
Once the pizza is baked, remove it from the oven and let it cool slightly.
Spread the chopped lettuce, salami, pepperoni, and red onion over the top of the pizza.
Drizzle the prepared vinaigrette over the chopped toppings.
Slice and enjoy!