A type of sandwich is a popular food item that can be made in many different ways. The KNUCKLE sandwich is made with two slices of bread and a filling of either HAM or cheese. A SUB sandwich is a long, thin sandwich made with a variety of fillings such as meats, cheeses, and vegetables. A HAM sandwich is made with two slices of bread and a filling of HAM. A TUNA sandwich is made with two slices of bread and a filling of TUNA. A HERO sandwich is a large sandwich made with a variety of fillings such as meats, cheeses, and vegetables. A Reuben sandwich is made with two slices of rye bread, corned beef, Swiss cheese, sauerkraut, and Russian dressing. An open-faced sandwich is a single slice of bread with a variety of toppings such as meats, cheeses, and vegetables.