Classic Peruvian ceviche with lime-cured sea bass

1. Boil the sweet potatoes in their skins for 30-35 minutes until tender, peel and cut into thick rounds; cook the Andean corn (choclo) in salted water for 10 minutes and cut the kernels off the cob in larger pieces – leave both to cool.

2. Slice the red onion into very thin half-moons, soak in iced water for 5 minutes (it becomes crisp and less sharp) and drain.

3. Cut the fish into 2 cm cubes, put in a cold glass bowl and salt – the fish must be very fresh and well chilled.

4. Halve the limes and squeeze them gently by hand (pressing hard would add the bitter oil from the skin), pour the juice over the fish; add the crushed garlic, seeded and finely chopped ají limo and half the chopped coriander and toss.

5. Leave for 2-3 minutes, until the fish turns opaque white outside but is still slightly translucent inside – don't marinate longer or it turns rubbery.

6. Stir in the red onion, pile onto plates with the marinade, add the sweet potato and corn alongside, sprinkle with the remaining coriander and serve immediately.

Tip: The spicy, fishy marinade left in the bowl is called "leche de tigre", tiger's milk – in Lima it's sipped from a small glass, as it's said to give you strength.