Cut the fish in 1/2-inch squares.
Soak in a mixture of the soy sauce and ginger for 15 minutes.
Drain, reserving the marinade.
Roll the fish in the cornstarch.
Heat the oil in a skillet; brown the fish in it on both sides.
Saute the onions in the remaining oil for 3 minutes.
Stir in the peas, sakt or sherry, sugar, Ac'cent, and reserved marinade and the fish.
Cook over low heat 5 minutes.