Veal spleen (milza in Italian, meusa in Sicilian) tastes a bit like calf's liver and is popular in central Italy as a kind of bruschetta (crostini di milza) and in Sicily as a sandwich stuffed in a mafalda roll, known as a vastedda or vastidda in the old days, but now as 'pan cà meusa'.
The Sicilians are said to have learned their love of milza from Palermo's Jewish butchers, who slaughtered the animals in the famous Vucciria market, and were paid in offal instead of money. To earn some of the latter, they set up stands along the street, boiling and frying the sliced spleen and selling it as sandwiches.
Since 1834, Palermo's famous Antica Focaccia San Francesco has been selling their caciocavallo and ricotta sandwiches schietto ('virgin', without the spleen) or maritata ('married', with spleen, and a squeeze of lemon).
Other regions of Italy partake as well. Rome's Jewish community makes milza di bue in padella (sliced and cooked in a frying pan with garlic, olive oil and sage, sprinkled with cinnamon and topped with reduced meat juices and vinegar). In Trentino they use it to make gnochetti with greens, garlic, marrow and egg. In neighbouring Alto Adige they make milzschnittensuppe (beef broth poured over spleen-covered crostini).