Wash fish and wipe dry. Cut into thick slices, and marinade overnight.
Using low heat, heat the ingredients for sauce. Cook fish pieces in sauce until sauce boils. Turn fish over until whole piece is coloured.
Heat oil in wok, and deep fry fish pieces for 2 mins. Take out, and dip again into the sauce. Let soak for half a minute, then deep fry again in oil. Repeat for three times, then serve hot or cold to your own liking.