This sweet, sour, and spicy condiment originated with Sri Lanka’s small Malaysian population. In the bowl of a small food processor or electric grinder, combine 10 dates, the mustard seeds, and ½ teaspoon white vinegar. Process into a thick paste. Transfer the date mixture to a bowl. Add the remaining dates and vinegar, the cashews, sugar, jaggery, chili powder, lime pickle, shallots, peppers, and cinnamon; stir well to combine. Taste and adjust the salt as desired.