Ingredients 

1. Curds - 2 cups (buttermilk about 4 cups)
2. Onion - 1
3. Green chillies - 4
4. Turmeric - a pinch
5. Salt - as required
6. Oil - 2 tsp
7. Seasoning - 1 tsp mustard seeds, 1/2 tsp of jeera, pinch of hing, few curry leaves and red chilli pieces

Method: 

1. To make Buttermilk - Churn the curds and add 2 cups of water. Add the required amount of salt.
2. Chop onions and green chillies into small pieces and add to the buttermilk.
3. Heat oil in a small pan and add red chillies, mustard seeds, jeera, a pinch of hing, curry leaves and a pinch of turmeric.
4. Add this to the buttermilk.