If you are using plaice, ask the fishmonger to remove the dark skin of the plaice or remove it yourself with a small, sharp knife.
Cut the fish fillets into 2.5cm/1in strips. Sprinkle them with a teaspoon of salt and the pepper. Set aside in the fridge for 15 minutes.
Beat the eggs in a small bowl. Coat the pieces of fish in cornflour and then beaten egg.
Heat a wok or large frying-pan over high heat until hot. Add the oil. When it is very hot and slightly smoking, turn the heat down to medium. Shallow-fry the fish pieces on each side, in several batches, until they are golden-brown. Drain them on kitchen paper. Pour off the oil and discard it.
Wipe the wok or pan clean. Add the rest of the ingredients and the remaining teaspoon of salt. Simmer for 2 minutes. Put the fried fish fillets on a warm serving platter and pour over the hot sauce. Serve at once.