Whisk egg, spring onions, ginger, Shaoxing wine, soy sauce, garlic, sugar, 1/2 teaspoon salt, and 1/2 teaspoon white pepper together in a bowl. Mix in chicken. Let marinate for 20 minutes.
Pour 1 cup plus 2 tablespoons sweet potato starch into a shallow bowl.
Heat oil to 340 degrees F (170 degrees C) in a large saucepan. Dredge chicken pieces in sweet potato starch; drop gently into the hot oil in batches. Cook until golden on the outside and no longer pink in the center, 2 to 3 minutes per batch. Transfer to a paper towel-lined plate using a slotted spoon.
Arrange lettuce leaves on a large serving plate. Place fried chicken on the lettuce leaves. Mix 1 tablespoon salt and 1 tablespoon white pepper together in a small bowl; sprinkle over chicken.
We have determined the nutritional value of oil for frying based on a retention value of 10% after cooking. Amount will vary depending on cooking time and temperature, ingredient density, and specific type of oil used.
Per Serving: 405 calories;19.2 g fat;
30.1 g carbohydrates;
27 g protein;
100 mg cholesterol;
1481 mg sodium.