Slit the chillies lengthways with a sharp knife. Discard the seeds and soak the chillies in hot water for 1–2 minutes, or until soft. Drain and roughly chop.
Using a mortar and pestle, pound the chillies, lemongrass, galangal, cloves, cinnamon stick, cardamom seeds and nutmeg into a paste. Add the garlic, shallots and coriander roots. Pound tog