Make the Pesto: Blend sun-dried tomatoes, basil, Parmesan, pine nuts, garlic, salt, and pepper in a food processor. Drizzle in olive oil until smooth.
Prepare the Ciabatta: Warm the ciabatta loaf in the oven and slice it horizontally.
Assemble the Sandwich: Spread pesto on the bottom slice of ciabatta. Layer with prosciutto, turkey, salami, and mozzarella.
Melt the Cheese: Broil the sandwich until the mozzarella is melted (optional).
Finish and Serve: Add shredded lettuce and chillies. Top with the other ciabatta slice, slice into 6 pieces, and serve.