2Marinate the fish with salt, ginger, and scallions for 10 minutes.
3Prepare the batter by combining cornstarch, salt, baking powder, baking soda, egg white, and club soda; mix until completely smooth.
4Coat the fish with the batter.
5Heat the oil to 350°F (177°C).
6Deep fry the fish for 4 minutes, carefully spooning hot oil over the fish.
7Remove the fish and drain.
8Prepare the sweet and sour sauce by combining chicken stock, ketchup, sugar, rice wine vinegar, salt, minced ginger, minced garlic, diced red and green peppers, cornstarch, and water.