Mix together the egg white, cornflour, half the sea salt and the cod, and leave for 10 minutes.
Heat a wok until almost smoking. Add the vegetable oil and, when hot, remove the fish from the marinade and stir-fry in batches until golden brown, then remove from the wok. Reheat the wok and stir-fry the carrot, spring onions, ginger and garlic until fragrant. Deglaze the w