Soak Tamarind, soak 1/2 cup tamarind in 1 cup warm water for 30 minutes. Mash it to separate the pulp from seeds and fibers.
Strain Pulp, strain the tamarind mixture through a sieve to get the liquid, leaving seeds and fibers behind.
Cook Chutney, in a saucepan, combine the tamarind liquid with 1 cup jaggery, 1/2 teaspoon cumin, 1/2 teaspoon black salt, and 1/4 teaspoon red chili powder. Cook until the jaggery dissolves and the chutney thickens, about 10-15 minutes.
Adjust Consistency and Flavor, if too thick, add water to adjust consistency. Taste and add more jaggery or salt if needed.
Cool, allow the chutney to cool to room temperature; it will thicken more as it cools.
Store and Serve, transfer to a jar and refrigerate for up to 2 weeks. Enjoy with snacks or as a tangy addition to meals.