Cook the noodles in a pan of boiling water for 2–3 minutes, until al dente, or according to packet instructions. Drain, then rinse under cold running water and drain again. Drizzle with a dash of sesame oil and toss through to prevent the noodles from sticking to each other.
Put the chicken strips in a bowl and season with a dash of light soy sauce, the five-spice powder and chilli sauce, if using. Mix well, then lightly dust the chicken strips with the cornflour.
Heat a wok until smoking and add the groundnut oil, then add the chicken and stir fry for 3–4 minutes, or until the chicken is golden-brown and cooked through.
Add the red pepper and stir fry for 1 minute, then add the bean sprouts and spring onion and stir fry for 30 seconds. Stir in the cooked noodles and season with the soy sauce, a dash of sesame oil and freshly ground black pepper.
Pile the noodles onto a serving plate and serve immediately.