Spicy Buttermilk

Spicy buttermilk is served after a heavy meal in most of the restaurants in India. Every restaurant has different way of making it. I tried and tried to get the taste which I liked. Finally I zeroed it on this recipe which we always liked.
Ingredients:
2 cups buttermilk
1″ piece ginger
2-3 green chillies
Salt
1-2 strands coriander leaves
Method:
Add finely chopped ginger, coriander leaves, chilies and salt to buttermilk (Alternatively, blend/grind all the ingredients together). Add sufficient water to make it thin. If needed a pinch of asafoetida(hingu) can be added.
Serves : 1-2
Preparation time : 5min