Panzerotti originated in central and southern Italy, especially in Apulia. They are small versions of the calzone or closed pizza, but produced with a softer dough. The most common fillings are tomato and mozzarella, but spinach, mushrooms, baby corn, and ham are often used. Another filling is onions stir fried in olive oil and seasoned with salted anchovies and capers, a seasoning that, mixed with bread, is also used in Apulia for stuffed bell peppers.