Marinate the chicken (15–20 minutes): In a bowl whisk egg white, Shaoxing, salt, cornstarch and light soy. Add chicken cubes, toss until coated, and let rest while you prep other ingredients. (Skip egg white for a simpler version.)
Mix the sauce: In a small bowl combine light soy, dark soy (if using), black vinegar, Shaoxing, sugar, and stock. Stir to dissolve sugar. Keep the cornstarch slurry separate.
Prep aromatics & veg: Mince garlic and ginger, slice scallions (keep whites/greens separate), chop bell pepper, measure peanuts and chilies.
Par-cook the chicken (velvet or sear):
Sear method (recommended for deeper flavor): Heat a wok or large skillet over high heat. Add 1 tbsp oil. Add marinated chicken in a single layer and sear 1–2 minutes per side until lightly golden but not fully cooked. Remove and set aside.
Velvet method (silkier finish): Bring a pot of water to a gentle simmer, add a splash of oil and the marinated chicken; blanch until just opaque (~1 minute). Drain and set aside.
Aromatics and chilies: Wipe the wok if needed, return to high heat and add remaining oil. Add dried chilies and stir quickly 15–30 seconds until fragrant (don’t let them burn). Add garlic, ginger and crushed Sichuan peppercorns; stir 10–20 seconds until aromatic.
Vegetables & peanuts: Add bell pepper and the white parts of scallion; stir-fry 30–45 seconds so they’re bright and slightly crisp. Toss in roasted peanuts to warm them through.
Combine & sauce: Return chicken to the wok. Pour the prepared sauce over and bring to a simmer for 20–30 seconds.
Thicken: Stir the cornstarch slurry, add it gradually while stirring until the sauce thickens and becomes glossy and clings to the chicken. Cook 30–60 seconds more to remove raw starch taste.
Finish: Stir in scallion greens and a drizzle of toasted sesame oil (if using). Give a final toss and remove from heat.
Serve: Spoon over steamed jasmine or short-grain rice. Garnish with extra peanuts and scallion slices.