Method:
Grind together the soaked chana dal , dhaniya seeds, jeera seeds , green chillies and Ginger to make it a thick paste.

Beat sour curd thoroughly, little water can be added if curd is very thick and dissolve the grinded paste in it.

Add a pinch of haldi powder and salt. Heat Oil, with hing , rai seeds and fry either one of the above vegetable. Transfer the above prepared curd mixture and bring to a boil over simmer flame.
Tips on how to avoid spoiling the 'curd' due to the heat :
Thorough beating of the Sour Curd is essential. When the mixture starts thickening, constant stirring is required. Kuzhambu should be allowed to boil at lower flame.