Combine the chow mein sauce ingredients in a small bowl and set aside.
Cook the thin egg noodles as per the packet instructions, less 1–2 minutes. Rinse in cold tap water, drain and set aside. They will continue cooking in the stir-fry.
Heat the oil in a large, deep, heavy-based pan over high heat and add the beef. Cook for 2–3 minutes until it changes from pink to brown, breaking it up with the back of your spoon. Stir 2 tablespoons of the chow mein sauce through the beef to season.
Add the eggs to the beef and cook, stirring, for 1–2 minutes until the eggs are cooked through (see note 1).
Add the cabbage and carrot and cook, stirring, for 1 minute until softened.
Add the chow mein sauce and cook, stirring, for 1–2 minutes.
Add the noodles, bean sprouts and spring onion. Use tongs to toss and cook for a further 1 minute until the spring onion and bean sprouts are heated through.
Drizzle with sesame oil and chilli oil, if using. Serve and enjoy!
