Ceviche

Ceviche is Peru's national dish — fresh, firm white fish cut into bite-size pieces and "cooked" by nothing more than the acid of freshly squeezed lime. Tossed with thin-sliced red onion, fiery ají chillies and coriander, the fish turns opaque in minutes and releases a bright, punchy marinade known as leche de tigre, or "tiger's milk."

It is traditionally plated with sweet potato and corn — both the toasted, crunchy cancha and the big-kernelled boiled choclo — whose mellow sweetness balances the sharp, spicy brine. Freshness is everything: a good cevichería buys the catch each morning and serves it at lunch, when the fish is at its peak and the citrus still has bite.

Ceviche's roots run deep along Peru's Pacific coast. Long before the Spanish arrived, coastal peoples such as the Moche were eating raw fish cured with the juice of fermented fruit, while the Inca preserved fish with salt and chicha. The dish took its modern form after Spanish colonists introduced limes and onions, marrying European citrus with indigenous fish and chillies.

Over the centuries it spread up and down the Pacific, and today Ecuador, Mexico, Chile and Colombia all serve proud regional versions. In Peru, though, it is far more than a meal: ceviche has its own national holiday on 28 June, is recognised as Cultural Heritage of the Nation, and anchors the cevichería — a lunchtime institution where the day's catch is judged by how clean and bright it tastes.