Use a very sharp knife and cut the fish
fillet into small and thin slices. Then coat the fish with cornstarch.
Heat a wok with oil over a high heat until smoking. Reduce the heat and
use chopsticks to add the fish slices into the oil and deep-fry for
about 2 minutes or until golden in color. Remove and drain. Heat up the lard in a hot
wok or pan. Meanwhile, mix the sugar,
soy sauce, vinegar, wine or sherry and cornstarch in a bowl. Toss the finely chopped
ginger root and onion into the hot lard, then pour in the sauce
mixture and stir until thickened. Now add the fish slices,
blend well so that each piece is coated with the sauce. Serve hot
with white rice.