Gather your ingredients. If your tamarind paste has seeds, soak it in hot water, then pick out the seeds.
In a saucepan over high heat add the tamarind, dates, jaggery or sugar, and two cups of water. When the mixture comes to a boil, turn the heat down to medium-low, or a low simmer, for 10 minutes. You are looking for the tamarind and dates to become very soft.
While the tamarind mixture is cooking, in a small pan over medium-high heat toast the cumin, coriander, and fennel seeds for a couple of minutes. Or until the spices are fragrant and the cumin seeds turn a shade darker. Stir frequently to ensure even browning and allow to cool for 5 minutes. Grind the spices in a spice grinder into a fine powder.
Once the tamarind and dates are softened, stir in the ground spices, chili powder, and salt. Cook for another 2 minutes. Cool for 10 minutes and process to a smooth paste in a blender. Add water if necessary.
Press the mixture through a sieve. Taste for salt and chili powder and dilute with some water if you are wanting a thinner texture.
The chutney will keep covered in the refrigerator for up to two weeks, and in the freezer for several months. You can always adjust the thickness with a bit more water after storing the chutney.