Grind together coriander powder, cummin seed, coconut and the salted mangoes to a fine paste. Crush four red chillies, green chillies and four sprigs of curry leaves. Mix all the ingradients in 11/2 cups curds and add salt to taste. Heat oil in a pan and add mustard, four red chillies and two sprigs of curry leaves and season. Pour it into the curd mixture. Stir and use.