Beat egg in a large bowl. Mix all-purpose flour and 1 1/2 tablespoons corn flour into egg until batter is smooth; season with salt and pepper. Dip chicken into batter, working in batches, until coated; place on a plate in a single layer so the pieces do not touch.
Heat a skillet over medium-high heat; add enough vegetable oil to reach about 1/2-inch depth. Fry battered chicken, working in batches, in the hot oil until no longer pink in the center, 5 to 10 minutes. Transfer cooked chicken, using a slotted spoon, to a paper towel-lined plate to drain.
Heat 2 tablespoons vegetable oil in skillet over medium heat; cook and stir ginger and garlic until lightly browned, 1 to 2 minutes. Add cilantro and serrano peppers; reduce heat to medium-low.
Mix chicken stock, soy sauce, sugar, 1/4 teaspoon black pepper, and monosodium glutamate into garlic-ginger mixture; cook and stir until sauce is heated through, about 5 minutes. Add green bell pepper to sauce and cook until slightly tender, 2 to 3 minutes.
Whisk water and 2 tablespoons corn flour together in a bowl until smooth; stir into sauce until incorporated. Bring sauce to a boil. Add chicken and stir to coat.
We have determined the nutritional value of oil for frying based on a retention value of 10% after cooking. The exact amount will vary depending on cooking time and temperature, ingredient density, and the specific type of oil used.
Per Serving: 328 calories;17.5 g fat;
12.7 g carbohydrates;
29 g protein;
116 mg cholesterol;
736 mg sodium.