Soak 1 cup (150 g) of seedless tamarind in 2 cups of hot water for 20 minutes.
Mash it well using your hands.
Keep a mesh strainer over a large bowl and strain the tamarind concentrate through it. Add 1 cup of hot water over the leftover pulp and strain it again. Keep pressing it with the back of a large spoon to get the maximum pulp.
Discard the leftover tamarind pulp in the strainer.
Transfer the tamarind water to a medium size pan.
Add 1 cup (250 g) of crushed jaggery, 2 teaspoon grated ginger, 1 teaspoon roasted cumin powder, 1 teaspoon Kashmiri red chili powder, 1 teaspoon coarse fennel powder, ½ teaspoon asafoetida, 1 teaspoon black salt, and ½ teaspoon regular salt to the pan and mix well.
Cook the mixture on medium heat for 10-12 minutes, stirring frequently. Add ¼ cup of raisins and cook the chutney for another 12-15 minutes, stirring frequently.
If the chutney has thickened too much, add some water to it and bring it to a boil. Check for salt and add more if needed. Remove the pan from the heat and bring down the chutney to room temperature.