To serve 3 you will require
Thick curd - 250 ml
Mustard seeds - 1/2 tsp
Dry red chilli - 2 nos, cut into pieces
Ginger paste - 1/4 tsp
Tumeric powder - 1/4 tsp
Curry leaves - few
Salt to taste
Oil - 1 tbsp
Method
Beat curd and add salt to it. If the curd is very thick then add few tablespoons of water and mix well.
In a sauce pan heat oil and put mustard seeds and let it splutter. Add curry leaves, dry red chilli, ginger paste and saute it well.
After a few seconds turn off the flame and add tumeric powder and mix well.
Let the tadka cool for a while, then add the beaten curd and mix it well.
Keep this mix on medium flame and stir it continuosly. DO NOT BOIL THE CURD MIX. Heating the liquid is required not boiling.
Now remove it from the flame and serve it with rice and achar.