Bring stock, chilli and soy sauce to the boil in a large saucepan over high heat. Add vegetables, reduce heat to medium and simmer, uncovered for 3 minutes.
Add noodles and chicken. Simmer for a further 3 minutes or until noodles separate and chicken is cooked.
Divide bean sprouts and coriander between 4 deep serving bowls. Ladle over hot soup. Serve immediately.