A meatball sub is a type of sandwich that features meatballs as the main filling. Typically, the meatballs are made from ground beef, pork, or a combination of meats, mixed with breadcrumbs, herbs, and spices. They are usually simmered in marinara sauce, which adds flavor and moisture. The sandwich is served on a long roll or hoagie bread, making it easy to hold and eat. To prepare a meatball sub, the meatballs are placed inside the bread and often topped with cheese, such as mozzarella or provolone. The sandwich is then baked or toasted until the cheese melts and the bread is slightly crispy. Meatball subs are popular in many regions, especially in Italian-American cuisine, and are often enjoyed as a hearty meal or snack.