Put ½ cup of deseeded tamarind, ½ cup of pitted dates, ½ cup of grated jaggery, ½ teaspoon of red chili powder, and 2 cups of water in a pot. Boil until the tamarind and dates are very soft.
Add ½ teaspoon of ground ginger, ½ teaspoon of roasted ground fennel, ½ teaspoon of roasted ground cumin, ¾ teaspoon of roasted ground coriander, and ½ teaspoon of black salt (kala namak). Simmer for 2-3 minutes.
Let cool. Blend until smooth, adding a little boiled and cooled water if needed, then press through a sieve.
