1. Flake the fish with a spoon. Mix the fish, curry paste, egg white, salt and sugar and knead with your hands. Mix through snake beans and kaffir lime leaves.
2. For the sweet chilli syrup, heat the sugar, vinegar, fish sauce and 2 tablespoons water in a saucepan for about 3 minutes or until the sugar has dissolved. Leave to cool. Place chilli and cucumber in a bowl and pour over cool syrup. Set aside until ready to serve.
3. Heat enough vegetable oil in a saucepan or wok to deep-fry. When the oil is hot, pinch off tablespoons of the fish mixture and carefully drop into oil. Cook in batches for 2-3 minutes or until golden. Drain on paper towel. Serve with sweet chilli syrup.
4. Note: snake beans are available from some Asian grocery stores. Substitute green beans if unavailable.