The Sandwich just appears in the episode I Heart Dancing. SpongeBob dances in the Krusty Krab with a tray full of Krabby Patties and throws them through the air, which land on the tables of the customers. Frankie gets a drink, Nachos, a sandwich, a pizza, and a knight instead.
A sandwich can be made with lettuce, tomatoes, pickles, pepperoni, onions, cheese, or other things. On top, there is a kind of sauce.