Dice the fish fillets in 2x2x2 cms cubes or thereabouts, Place in a bowl and cover with lime juice. Place in the fridge for at least 30 minutes for the fish to 'cook'.
Once fish has changed its colour to a whiter tone, seared, bring out of the fridge and drain the lime juice.
In a new bowl, add the orange juice, tomatoes, onion, coriander and chillies. Mix all together adding salt and olive oil.
Serve with tostadas or totopos