1Combine all of the sauce ingredients except the cornstarch and 3 tbsp water in a small saucepan over high heat. Stir often while bringing mixture to a boil. Combine corn starch and 3 tbsp of water to make a slurry in a small ramekin. Pour this mixture into the sauce. When sauce begins to thicken remove it from heat.
2Slice chicken into bite-size pieces. Remove exactly 1 cup of the marinade from the pan and pour it over the chicken in a bowl. Cover and let marinade at least 30 minutes.
3Heat 4 inches of vegetable oil in a wok or skillet to 350 degrees F.
4Beat together the ice water and egg in a medium bowl. Add baking soda and salt. Add 3/4 to 1 cup of the flour and stir with a fork just until the flour in blended into the mixture. The batter should be slightly thick and lumpy.
5Dredge the chicken in the remaining flour and remove any excess flour, dip in the batter and fry in the hot oil for about 3 minutes or until golden brown. Remove from oil and drain well. Pour out all but 3 tbsp of the frying oil and heat wok to high. Add the chicken back to the wok and coat with sauce. Cook for about 1 minute until chicken is well coated.