Firstly, take equal quantity of fennel seeds and candy sugar, add cardamom pods and blend everything to a fine powder. Saunf sugar powder stays good for months, you can store in air tight glass jar and set aside.
Secondly, soak this saunf powder in 3.5 cups of water for 6 + hours or overnight in a clay pot.
Now soak 8 dry black grapes in the same clay pot. Alternatively, you can soak separately.
After 6 hours or following day, stir well everything.
Now strain juice with help of a strainer or a muslin cloth. Squeeze collected fennel powder residue and dry black grapes to extract all juices completely. Add ½ cup water, mash or blend everything together to extract all juices.
Finally , add 1.5 tablespoon of lime juice, ¼ teaspoon black salt and ¼ teaspoon roasted cumin powder.
Mix well everything, add some mint leaves, ice cubes and serve chilled.