Place the soy sauce, tomato ketchup, white wine vinegar, chilli sauce, brown sugar, chicken stock, sesame oil in a jug. Blend the cornflour with 2 tsps cold water, then add to the other ingredients. Mix thoroughly.
To use, just heat through until the sauce becomes thick. Alternatively if making a stir fry, place in the wok at the end of cooking and heat through until thick.