For the chilli hoki, in a shallow bowl mix the self-raising flour, cornflour, chilli flakes and salt and freshly ground black pepper together.
Dip the chopped hoki into the beaten egg white and then roll in the flour mixture to coat.
Heat the vegetable oil in a non-stick frying pan, add the hoki and fry for 1-2 minutes on each side, or until golden-brown.
For the tamarind ketchup, mix all the tamarind ketchup ingredients together in a small pan and heat gently for 1-2 minutes, then pour into a small dipping bowl.
To serve, place the chilli hoki on a serving plate and serve with the tamarind ketchup. Garnish with the lime wedges and coriander.