In a large non metallic bowl, combine the chicken, chilli, chilli flakes, garlic, spices, sultanas and nuts. Marinate for 2 hours or overnight.
Heat the olive oil in a frying pan and add the chicken and marinade. Bring to the boil for 5 minutes then add the lemon zest and juice and orange juice. Reduce the heat and simmer for 7 to 10 minutes. Garnish with the chopped herbs.