1. Pour 1½ cups water into a small saucepan, add the tamarind, and whisk until it has dissolved and formed a tart, muddy brown liquid. Add the jaggery and dates, and bring to a boil over medium heat. Boil, uncovered, stirring occasionally, until the liquid has evaporated by almost half, about 10 minutes. Remove the pan from the heat and allow the sauce to cool for about 5 minutes.

2. Transfer the dark brown, thin sauce and cooked-but-chunky dates to a blender jar and puree, scraping the inside of the jar as needed, until it forms a pancake-batter-thick, milk-chocolate-colored, tart-sweet sauce.

3. Transfer the sauce to a tightly sealed container (preferably glass, stainless steel, ceramic, or plastic because of the highly acidic tamarind) and store it in the refrigerator for up to 5 days or in the freezer for up to 2 months.