Step 1Place the water and tamarind paste in a small saucepan and simmer until the paste is softened.
Step 2Place the coconut, chile, ginger, chana dal, tamarind paste mixture and salt in a blender container and puree until smooth, about 5 minutes. Transfer to a bowl and set aside.
Step 3Heat the oil in a small skillet over medium-high heat to the smoking point and add the mustard seeds. Cover to avoid any oil splatters. After the mustard seeds pop, toss in the curry leaves and cover again, 30 seconds. Remove from the heat and add to the bowl. Mix thoroughly.