Codor a similar thick-flesh fish cut into long strips about 3/4 inch thick.
Oliveoil - not extra virgin
Sift the flour and cornflour into a bowl.
Make a well in the centre and gradually whisk in the coconut milk and fizzy water until you have a smooth batter.
Cover with a cloth and leave to rest at room temperature for up to 2 hours whisking vigorously every so often. It needs at least 45 minutes resting and whisking to activate the flour.
Note - a teaspoon or two of baking powder can be added to make a lighter batter on cooking but this should give a good thick coating.
For the fish
Cut cod into thin strips and dredge in lots and lots of flour to dry the flesh.
Prepare a pan for shallow frying. Use a good oil, preferably olive oil, and keep the temperature frying got but on the lower side of hot so not to destroy the oil. Depth should be half the thickness of the fish strips so half an inch will be fine.
Dunk the fish into the batter and introduce into hot oil as individual pieces.
Fry in batches allowing them to drain in a warm place before serving.