Mozzarella in carrozza con alici, mozzarella in a carriage with anchovies, is the Naples fried-cheese sandwich with a salt fillet hidden in the centre. A slice of mozzarella is closed between two pieces of bread, but before the package is sealed a salted anchovy is laid flat against the cheese so it is buried out of sight. The whole thing is dipped in beaten egg and fried until the outside sets into a crisp gold shell. What defines this version is what happens when you bite through that shell: the cheese pulls into hot threads and the anchovy, which has half-dissolved into the molten centre, hits as a sharp saline note that the plain carriage does not have. The fillet is concealed on purpose so the salt arrives as a turn inside the melt rather than a topping you can see.
The craft is moisture control, the seal, and the placement of the fish. Fresh mozzarella is wet, and wet cheese steams the crust soft and bursts the carriage in the oil, so the cheese is drained and pressed dry before it goes anywhere near the bread. The anchovy is set against the centre of the cheese, not the edge, so its oil and salt stay trapped where the melt is hottest and do not bleed into the crumb or the frying oil. The bread edges are pressed together and often sealed with the egg so nothing escapes once the inside loosens. Heat is then managed so the exterior colours at the same moment the centre flows and the anchovy gives way, the same timing problem as any griddled cheese sandwich, executed fast and hot. Cut too soon and the centre runs and the salt note never builds; the seal has to hold until you break it with the teeth.
The named turns stay on the same enclosed-melt logic: the plain mozzarella in carrozza without the fish, where the cheese stands alone, and the wider family of the pressed Italian bar toast that solves the same trapped-melt problem by welding rather than frying. Each of those is the same molten centre in a sealed shell, and each deserves its own article rather than being crowded in here.