Bring the milk to a boil in a deep, thick-bottomed non-stick pan. Add the lemon juice and stir till the milk curdles. Strain and immediately refresh the chhenna in chilled water.
Put the chhenna in a piece of muslin and squeeze till all the water is drained out.
Knead the chhenna well with the heel of your hand. Add caster sugar and cardamom powder, and knead again.
Cook in a non-stick pan on medium heat for eight minutes. Remove from heat and divide into twelve equal portions. Roll each portion into a ball and make a dent on the top.
When cooled, place a pistachio in the dent and serve.
Makes 12 sandesh/350 grams