Squeeze some lemons, you will need 1.5 tblspn of lemon juice, line a sieve with muslin cloth and place it over a big bowl.
Take milk in a pot and put it on high heat. Let it come to a boil. Once it boils, take it off the heat and let it sit for 1 min.
Now add in lemon juice and mix gently. The milk will curdle. Once a greenish whey separates from the milk and the milk solids have curdled completely. Strain it in the sieve.
Now take a big bowl of cold water and wash the chenna well. rinse it in three changes of water.
Now squeeze it gently with your hands to remove any excess whey water, Tie a knot and hang it over a tap and leave it to drain for 30 mins. I squeezed occasionally to make things faster.
After 30 mins, take the chenna in a bowl and knead it gently, by rubbing with your palms and knuckles till you get a soft dough.
Once a dough is soft, take a small portion from it and roll it in your palms gently till you get a smooth ball. now roll it little oval shape like.
Repeat with the remaining dough as well.
Now take sugar and water in a big pot and mix well so the sugar is melted. Once the sugar is melted, put it on stove and let it come to a rolling boil.
Now drop the balls into the sugar water and cover it with a tight lid and cook it for 8 to 10 mins till the ball has tripled in volume.
Now take it off the heat and let it sit for 15 mins.
Now open the lid and transfer it to a bowl and add in cardamom powder and mix well.
Now for making cham cham, take one and slit it open, fill it with sweetened khoya and top with pistachios. Roll in desiccated coconut and set aside.