Make the paste by putting its ingredients,roughly chopped,in a food processor with a few tablespoons of water till it is pureed.
Heat the oil in a saucepan and lightly fry the cinnamon,star anise and cardamom for two to three minutes stirring constantly. Add the paste and fry,always stirring,for five minutes.
Add the coconut milk,lemongrass,tamarind,sugar,lime leaves and a couple of pinches of salt. Stir and simmer for 20 minutes uncovered.
Add the chicken and the long chillies and continue to simmer gently for an hour or so,stirring every 10 minutes,till the liquid has concentrated and sticks to the chicken pieces.
Serve with steamed jasmine rice.