Put the cod in a bowl and cover with cold water. Cover and leave to soak, in the fridge, for 12 hours, changing the water at least once.
Mix together the flours, baking powder, salt, sugar, egg yolk and buttermilk until you have a paste.
Whisk the egg white to soft peaks and fold into the paste.
Heat a tablespoon of the vegetable oil in a frying pan and cook spoonfuls of the mixture for 1–2 minutes on each side, until puffed and golden. Keep the pancakes warm in a low oven.
Drain the fish and pat dry. Heat the remaining vegetable oil in another frying pan and sear the cod for 2 minutes on each side. Add the garlic, chilli sauce, sherry, soy and sesame oil and cook for a couple of minutes to glaze the fish. Remove the fish from the pan and flake into chunks.
Toss the vegetables with the herbs. Top the pancakes with the vegetables and the cod and serve.