Put the chicken stock in the slow cooker and add the chilli, put the slow cooker on low and leave for 10 minutes.
Pan fry the chicken in the oil until brown.
Drain the liquid in the pan.
Add the onion and capsicum and cook for 2 minutes.
Stir in the curry paste, cook for 1 minute or until fragrant.
Add your mixture to the chicken stock and chilli.
Stir in cornflour.
Add fish sauce & coconut milk, stir well and cook on low for 2 hours.
After 2 hours add the buk choy, mushrooms and zuchinni.
Cook for a further 2 hours on low.
Serve how it is or with vermacelli noodles