Pan con Pejerrey

The sandwich grew out of the fishing life of Callao, Peru's first port, where silverside hauled in at dawn became the fishermen's early meal. Like much of the port's food it carries a mixed inheritance — the egg-and-flour batter and frying technique are usually traced to Italian and Japanese cooks who settled the coast — but firm, dated authorship is thin, so it is best understood as an everyday product of that immigrant-port kitchen rather than a single invention.

The crust crackles and the fish inside is hot, white and delicate, a clean mild sweetness with the faint salt of the sea. Salsa criolla lands sharp on top — lime and raw onion cutting the fry — and the soft roll catches the steam and a little oil. Light for fried food, the kind of thing eaten standing up.

A thin egg-and-flour coating seals the slim fillets so they steam-cook inside while the surface fries crisp; pejerrey is small and quick-cooking, so the oil must be hot and the fry brief or the fish dries. The acidic onion relish does double duty — it lifts the flavor and cuts the fat — and assembling the sandwich the moment the fish leaves the oil keeps the crust from going soft.