Ceviche Clasico Peruano

Ingredients

• 700g very fresh sea bass, sole or corvina fillet, skinned and pin-boned
• 12-14 limes, ideally small thin-skinned Peruvian limes (about 250ml juice)
• 1 large red onion
• 1 aji limo chilli, or 1 small habanero
• 1 small rocoto chilli, or 1 red bird's eye chilli
• 3cm piece fresh ginger
• 1 garlic clove
• 1 small bunch coriander, leaves only
• 2 tsp fine sea salt
• 2 medium orange sweet potatoes (camote)
• 2 ears of choclo or regular sweetcorn
• 1 tbsp caster sugar
• 100g cancha serrana (toasted Andean corn), to serve
• 2 crisp lettuce leaves, to serve

Before you cook

• Chill a large glass or ceramic mixing bowl in the freezer for 15 minutes
• Pat the fish completely dry, then cut it into 2cm cubes and keep it on ice in the fridge
• Peel the red onion, halve it through the root and slice it into paper-thin half moons
• Soak the sliced onion in a bowl of ice water for 10 minutes, then drain and pat dry
• Deseed the aji limo and slice it into fine rings, and finely mince the rocoto
• Peel and grate the ginger and garlic to a paste
• Roll the limes hard under your palm on the worktop to loosen the juice
• Peel the sweet potatoes and cut them into 2cm thick rounds
• Shuck the corn and snap each ear in half

Steps

1. Put the sweet potato rounds in a saucepan, cover with cold water, add the sugar and a pinch of salt, and bring to the boil.
2. Simmer the sweet potato for about 15 minutes, until a knife slides in with no resistance, then drain and set it aside to cool.
3. Bring a second pan of salted water to the boil and drop in the corn.
4. Boil the corn for 12 minutes, then drain it and cut each half into thick wheels.
5. Halve the limes across the middle and squeeze them by hand over a sieve, pressing only gently so no bitterness comes out of the pith.
6. Stop squeezing before the rind starts to fold inside out, and discard any lime that tastes bitter.
7. Take the chilled bowl from the freezer and tip in the cubed fish.
8. Scatter the salt over the fish and turn it through with a metal spoon for 30 seconds, which draws out surface moisture and helps the acid grip.
9. Add the ginger and garlic paste, the minced rocoto and half the aji limo rings, and stir once.
10. Pour the lime juice over the fish so every cube is submerged.
11. Stir gently and leave the ceviche for exactly 2 minutes, until the outside of the cubes turns white but the centres stay translucent.
12. Taste the milky juice at the bottom of the bowl, which is the leche de tigre, and adjust it with salt or more lime.
13. Fold in the drained red onion and most of the coriander leaves, and stir for 10 seconds only.
14. Line four shallow bowls with a lettuce leaf and spoon in the fish along with plenty of the leche de tigre.
15. Tuck the sweet potato rounds and corn wheels alongside.
16. Scatter over the remaining aji limo rings, the last of the coriander and a generous handful of cancha, then serve straight away.