Slice the beef into thin strips and place in a glass or ceramic bowl with all the ingredients for the marinade. Toss to coat evenly, cover and leave to marinate in the refrigerator for 3–4 hours, or overnight if time permits.
Trim the sugar snap peas, cut the carrots into thin matchsticks and halve the baby corn lengthways.
Spray a large nonstick wok or frying pan with cooking spray and heat over a high heat. Add the beef mixture and stir-fry for 2–3 minutes until browned and sealed.
Add the chilli and onion to the pan and stir-fry for 1 minute, then add the remaining vegetables and stir-fry for a further 1–2 minutes. Add the stock and soy sauce and stir well.
Bring to the boil, add the cornflour paste and stir to mix thoroughly. Cook, stirring constantly, for 2–3 minutes until the mixture has thickened.
Remove the pan from the heat and season to taste with salt and white pepper. Ladle into warmed bowls and serve with steamed rice and shredded spring onion to garnish.