Combine 500 grams chicken thighs, diced into cubes with 2 teaspoons white pepper, 1 tablespoons rice vinegar (for marinade), 1.5 tablespoons corn starch (for marinade), 1 egg white, and 1 pinch salt, to taste. Mix well until every piece is evenly coated, then let it rest for 20 to 30 minutes
Prepare the sauce: Add 2 tablespoons oyster sauce, 2 tablespoons dark soy sauce, 2 tablespoons light soy sauce, 1.5 tablespoons vinegar (for sauce), 2 tablespoons brown sugar, 1 teaspoons black pepper, 1 teaspoons chicken powder, 1 teaspoons paprika, 1 teaspoons onion powder, 1 teaspoons Sichuan pepper (optional), 1.5 tablespoons corn starch (for sauce), and 80 milliliters water into a jar. Seal and shake thoroughly until the corn starch is fully dissolved and the sauce is smooth with no lumps. Set aside.
Heat 3 tablespoons peanut or neutral oil in a wok or large pan over high heat. Stir-fry the marinated chicken in batches until golden brown and cooked through. Remove from the wok and set aside.
In the same wok, add 5 garlic cloves, thinly sliced, 1 fresh ginger, thinly sliced (1 inch piece), 6 dried red chilies, and 2 spring onions, white part only. Stir-fry for 1 minute.
Give the sauce jar a quick shake and pour it into the wok. Let it simmer until it thickens and turns glossy. Add a small splash of water if it tightens up too much.
Return the cooked chicken to the wok and toss well in the sauce for about 1 minute until every piece is fully coated.
Finish and serve: Add 60 grams dry roasted peanuts, 2 spring onions, green part (for garnish), and 1.5 tablespoons sesame oil. Toss quickly, turn off the heat, and serve immediately with steamed rice.