1 inch piece
Fresh mint leaves
Black salt (kala namak)
Dry roast cumin seeds till dark brown and fragrant. Slice ginger. Halve 2 lemons and remove seeds and quarter each half. Put ginger and fresh mint leaves in a mortar and crush with a pestle. Put this mixture into a cocktail shaker.
Similarly crush 3-4 lemon pieces and add to the shaker. Squeeze the juice of the remaining lemon pieces into the shaker. Add another 1 tbsp lemon juice, salt and black salt.
Cool cumin seeds and crush in a clear mortar and pestle. Add ¾ tsp of crushed cumin seeds into the shaker along with a few ice cubes and ¼ cup water and shake well.
Strain into serving glasses, add a few of the crushed lemon pieces. Fill up the glasses with drinking soda, stir well and serve immediately.