Using a food processor or mortar and pestle, blend shallots, garlic, lemongrass and galangal to a paste with oil, turmeric and chilli jam. Put into a large dish with oxtail pieces, tomato and tomato purée and marinate for 2 hours or overnight.
In a large pot, bring stock to simmering point with tamarind liquid and palm sugar. Add oxtail and its marinade, chilli