Take a big pan, add milk to it, and put on medium flame. Boil the milk by stirring continuously, once the milk starts to boil, switch off the heat. Keep the milk aside for 2 to 3 minutes.
Now in a small bowl add vinegar and water, mix it. Pour this liquid into the boiled milk and wait till the milk gets curdled. Now the chenna and the greenish water will be separate.
Pour this over a soft cotton cloth or a strainer to remove the whay and pour two cups of cold water on it to remove the sourness of vinegar. Squeeze gently the cotton cloth to get all the extra water out. Hang the chenna along with a cotton cloth for 5 minutes.
Transfer the chenna to a mixer pot, add sugar, cardamom, thandai powder, rose water, rose essence, and dissolve saffron strings.
Give a speedy churn to the chenna mixture and get a firm paste.
Set a steamer with water and switch on the heat to bring water to boil.
Now grease your cheesecake tin with ghee.
Transfer the chenna mix into it.
Place the tin in the steamer, cover it with a lid and steam it for 20 minutes or till the toothpick comes out clean.
Take out the steamed chenna and set it aside to cool to room temperature.
Now refrigerate it for 2 to 3 hours.
Take out the chilled chenna by uplifting the cake mold. Pour chilled rose rabri on top of it. Sprinkle Few strains of saffron on top.