1. Cut the fish along the grain into 2 1/2 inch X 1/2 inch strips.
2. Place the fish in a bowl and marinade in the marinate ingredients. Sprinkle with flour and set aside.
3. Into a well dried large bowl pour the egg whites. Whip until it stiffens. Add the cornstarch and flour and blend to make the batter.
4. Pour oil into a wok and heat to 338°F. Dip one piece of fish at a time into the batter, coat in it, then drop it into the oil. When all the pieces are in the wok, turn the heat to high and continue frying until the color changes, scooping oil with a ladle and pouring it over the fish.
5. Place the fried fish on a platter, garnish with lettuce leaves and serve with catsup and pepper salt as dippings.