Step 1 Put noodles into a bowl and cover with boiling water. Stand for 5-8 minutes or until tender. Drain. Rinse under cold water. Return to bowl.
Step 2 Fill wok 1/3 full of cold water and bring to the boil. Reduce heat and add chicken fillets. Gently simmer for 8-10 minutes or until cooked through. Remove chicken with a slotted spoon and transfer to a plate. Shred or thinly slice.
Step 3 Add cauliflower to wok and cook for 3-5 minutes or until just tender. Drain, reserving 1 cup of liquid. Set aside. Combine brown sugar, soy sauce, vinegar and cornflour in a jug.
Step 4 Clean wok. Add oil and swirl to coat sides. Heat wok over high heat. Add onion, capsicum and green beans. Stir-fry for 3 minutes or until vegies are just tender. Add reserved liquid, cabbage and cauliflower to wok. Stir until well combined. Add chicken, noodles and sugar mixture. Stir until well combined. Bring sauce to the boil. Reduce heat. Cook until sauce thickens. Divide between 4 bowls. Serve immediately.