Add 2 cups of milk in a vessel and once this reaches the boiling consistency just keep the flame low and allow the milk to reduce into 1 to 1 and 1/4 cups.
Meanwhile, boil the remaining 2 cups of milk in a vessel, and once when it comes to a boil, add the lemon juice to this. Dilute the lemon juice with 1 tsp of water.
Now you can see the water start separating.
switch off the flame to avoid overcooking and drain with a clean muslin cloth.
Wash this nicely in running tap water. This step is to get rid of the sour taste of the lemon in the paneer.
Add this Paneer to the boiling milk and mix well.
Keep the flame low.
Add sugar and cardamom powder to this and mix well.
Saute this nicely without getting burnt, till the moisture leaves and this becomes a whole mass.
This took approximately 11 minutes for me.
Grease a plate with ghee and keep it aside.
Once the milk + paneer combo comes into a mass transfer this to the plate greased with ghee.
Keep this in the refrigerator for half an hour.
After that, cut them into squares and garnish them with sliced pistachios.