Heat the milk until the milk comes up. Set aside until the milk cools to lukewarm.
In a sufficiently big bowl add the curd and spread it to the sides. Crush all the lumps.
Pour the warm milk into the bowl put a lid and set aside in a warm corner undisturbed.
In my place where the temperatures hover around 26⁰C-31⁰C the curd will set fine but where it is cold you may have to cover it with a kitchen napkin. In Delhi, my mother used an old woollen cap to cover the bowl.
The milk will set and form a thick curd in 8 hours.
Refrigerate until cold for about 2 hours so that the yoghurt thickens.
In a fine sieve layer with cheesecloth in the form of a T and place over a bowl big enough to hold the sieve.
Spoon the cooled curds on to the cheesecloth, cover and refrigerate for 8 to 24 hours, depending on how thick you want your Greek Yogurt.