Starting at the tail end of the fillets, skin them using a sharp knife.

Slide the knife back and forth along the length of each fillet, pushing the fish flesh along as you go.

Cut the fish into even-sized pieces, about 5 cm (2 inch)es.

Mix together the egg white, cornflour, wine, salt and pepper. Place the fish in the mixture and leave to stand while heating the oil.

When the oil is hot, fry a few pieces of fish at a time until light golden brown and crisp. Remove the fish to paper towels to drain, and continue until all the fish is cooked.

Remove all but 15 ml (1 tbsp) of the oil from the wok and add the onion. Stir-fry the onion for 1 - 2 minutes and add the curry powder. Cook the onion and curry powder for a further 1 - 2 minutes. Add the juice from the pineapple and mandarin oranges and bring to the boil.

Combine the cornflour and lime juice and add a spoonful of the boiling fruit juice. Return the mixture to the wok and cook until thickened, about 2 minutes. Taste and add sugar if desired. Add the fruit, water chestnuts and fried fish to the wok and stir to coat. Heat through 1 minute and serve immediately.