Ingredients
For vada:
2 cups urad dal
Salt to taste
2 tsps chopped coriander leaves
6 green chillies, chopped finely
A pinch of soda bicarb

For dahi:
10 tablespoons yoghurt, diluted with water to
get the required consistency.
Salt to taste
A large piece ginger, crushed very finely
1 tsp mustard seeds
A pinch of hing
1 sprig curry leaves
Oil for seasoning

Method
Soak the urad dal in hot water for about 1 hour.
Blend in a food processor using very little 
water till you get a smooth dough.
Mix in all the remaining vada ingredients.
Make small balls of the dough and deep fry in 
hot oil till golden brown.
Drain and set aside.
Let it cool to room temperature.

Add the ginger and salt to the diluted yoghurt 
and whisk well till it becomes very smooth.
Prepare the seasoning with mustard seeds, curry 
leaves and hing.
Add to the curds and mix well.
Now add the cooled vadas and mix well.
Serve as a snack.
Refrigerate whatever is remaining and do not re-heat.