Drain the soaked lentils in a colander for 10-15 minutes.
Meanwhile, peel and grate the raw mango.
In a mixer / food processor, coarsely grind the soaked lentils. Remove this into a bowl.
Add to this the grated raw mango.
In a small pan, dry roast the cumin seeds until fragrant - 4-5 minutes on medium flame. Pound this to a coarse powder, keep aside.
In a small pan or a tempering ladle, heat the oil. Add the mustard seeds, dried chillies curry leaves, red chilli powder and asafoetida. Once the mustard splutters, transfer this into the bowl, along with the powdered cumin.
Gently toss all the ingredients together along with the salt.
Garnish with fresh coconut and serve chilled.