In a mixing bowl, combine the chicken pieces with 1 tablespoon soy sauce, ginger garlic paste, cornstarch, all-purpose flour, and a pinch of salt. Mix well so each piece is coated.

Heat oil in a wok or deep skillet over medium-high heat. Drop the chicken pieces in batches, avoiding overcrowding the pan. Fry until golden brown and crispy. Verify the internal temperature reaches 74°C / 165°F at the thickest piece. Remove with a slotted spoon and drain on paper towels.

Discard most of the frying oil, leaving about 1 tablespoon in the wok. Heat over high heat, then add the chopped garlic, ginger, green chilies, and spring onion whites. Stir-fry for about 30 seconds until fragrant.

Add 1 tablespoon soy sauce, red chili sauce, and vinegar to the aromatics. Pour in the water or chicken broth and bring the mixture to a simmer.

Stir in the cornstarch slurry and cook for 1 minute until the sauce turns glossy and thickens. Add the fried chicken pieces and toss quickly until the sauce coats every piece.

Turn off the heat, garnish with chopped spring onion greens, and serve hot.