Put stock in a sauce pan, place over high heat and bring to a boil.
Add chicken pieces and simmer for about 10 minutes.
Add the cornflour mixture and cook till the chicken is tender.
Add the onions, carrots, celery, salt, soya sauce, chilli sauce and vinegar and simmer for 2-3 minutes and serve.
A luscious healthy slurp made with chicken, mushrooms and bok choy.