450g/1lb white fish fillets, skinned and cut into thin strips
1 red onion, thinly sliced
juice of 6 limes
2 tbsp olive oil
a pinch of sugar
4 tomatoes, seeded and roughly chopped
1 red chilli, diced
1 ripe avocado, peeled, stoned and diced
2 tbsp chopped fresh coriander (cilantro) plus extra to garnish
salt and ground black pepper
tortilla chips to serve
1 Put the fish strips in a bowl with the red onion. Pour over the lime juice and sprinkle lightly with salt. Cover and chill in the refrigerator for 24 hours, turning the fish occasionally.
2 Drain the fish and red onion from the marinade and mix with the oil, sugar, tomatoes, chilli, avocado and coriander. Season to taste with salt and pepper.
3 Divide among four serving plates, sprinkle with coriander and serve with tortilla chips.