Cut chicken thighs into bite size pieces, set aside
In a large saucepan, brown onion and garlic in the oil, then add chicken pieces and cook for 5 minutes.
Add mushrooms and the whole jar of Hoi sin sauce plus half the jar filled with water. Stir in chillies and add 1 bunch of the chopped coriander including stalks, season to taste. Simmer until chicken is tender. Add a little more water if needed, before serving add other bunch of coriander.