Prep the chicken. Thinly slice the chicken against the grain. In a bowl, mix soy sauce, cornstarch, sesame oil, and white pepper. Toss with the chicken and let sit for 10 minutes while you prep the rest.

Mix the sauce. In a small bowl, whisk soy sauce, oyster sauce, hoisin, sugar, sesame oil, water, and cornstarch until smooth. Set aside.

Cook the noodles. Boil according to package directions until just tender. Drain and rinse briefly under cold water to stop cooking. Toss with a splash of oil so they don’t stick.

Heat the pan. Use a large wok or wide skillet. Add 1 tbsp oil and heat until shimmering over medium-high to high heat.

Stir-fry the chicken. Add the chicken in a single layer. Let it sear for 30 seconds before stirring. Cook 3–4 minutes until lightly browned and just cooked through. Transfer to a plate.

Cook the vegetables. Add another tablespoon of oil to the pan. Toss in onion, carrot, and bell pepper. Stir-fry 2 minutes until slightly tender but still crisp.

Add aromatics. Push the veg to the sides, add a little more oil if needed, then add garlic and ginger to the center. Stir 20–30 seconds until fragrant—don’t let it burn.

Add cabbage and sprouts. Stir-fry 1–2 minutes until the cabbage wilts slightly but keeps some bite.

Combine everything. Return the chicken to the pan. Add the noodles. Pour in the sauce and toss quickly with tongs to coat evenly. Cook 1–2 minutes until the sauce thickens and clings to the noodles.

Finish and season. Stir in sliced scallions. Taste and adjust with a splash of soy sauce, a pinch of sugar, or a little water if it’s too salty or thick. Add chili oil if you like heat.

Serve hot. Top with toasted sesame seeds if you like. Eat immediately for the best texture.