Grind together coconut, green chillies and jeera to a smooth paste using a little water if required.
Mix the ground paste to the curd till it is all well blended.
Heat oil in a small tadka pan and add mustard seeds, methi seeds and fry till they crackle. Add heeng, dry red chillies and curry leaves and sautee for 2 minutes.
Pour this over curd and serve with steamed rice.