Mix together the cayenne pepper, pepper salt and thyme in a bowl and add the chicken and toss through to coat.
Heat the oil in a pan add the onions garlic, green peppers and celery cook on a low heat for 5 minutes stir occasionally. Add the chicken and cook for another 5 minutes until chicken is golden. Stir in ham, chorizo, tomatoes, tomato paste and stock bring to the boil.
Transfer the mixture to the slow cooker cover and cook on low for 6 hours. Add the prawns and rice, recover and cook on high for 30 minutes.