The muffuletta was invented at Central Grocery in New Orleans' French Quarter in 1906, created for Sicilian immigrant workers who wanted a single-handed lunch that could sustain them through a long day. A round loaf of soft sesame bread is split and filled with layers of Genoa salami, ham, mortadella, and provolone, then crowned with a chunky olive salad that has been marinated in olive oil, vinegar, and herbs until sharp and briny.
The sandwich is traditionally served at room temperature and improves as it sits — the olive salad soaks into the bread and the flavors meld over an hour or two. A full muffuletta feeds four to six people and is one of the great shareable sandwiches in American food. Make the olive salad a day ahead if you can; it only gets better.