Rajasthani Dhungari Chhaach (Smoked buttermilk)

Ingredients

Curd (dahi) (1 cup)
Green chillies, crushed (1-2)
Ginger, crushed (1 inch)
Salt (to taste)
Rock salt (1 tsp)
Cumin powder (jeera) (1 tsp)
Water (as required)
Oil (1 tsp)
Asafoetida (hing) (a pinch)
Mustard seeds (sarson) (1 tsp)
Coriander leaves (hara dhania), chopped (1 tbsp)
Mint leaves (1 tbsp, optional)
Bay leaf (tejpatta) (2)
Coal (2)
Desi ghee (1 tbsp)
Cumin seeds (jeera) (1 tsp)

Method

In a bowl, add curd, crushed green chillies and ginger. Whisk it. Now, add salt, rock salt, jeera powder and water. Blend all the ingredients using a blender.
Now heat oil in a pan. Once it is hot, add hing and sarson.
As the sarson starts crackling, remove it from flame and pour it on top of the buttermilk.
For dhungar, place a bay leaf, pieces of live coal in a heatproof bowl and pour hot ghee over it. 
Now add jeera to it.
Then put this bowl in a big vessel and cover it immediately with a lid to prevent the smoke from escaping.
After sometime, remove the smaller bowl from the big vessel, pour chaas in it and cover it again for 20 min.