Put the roasted chana dal, ginger, coriander leaves, coconut, chillies and lime juice in a blender and process until ground.
Transfer to a bowl.
Heat the oil for the tempering in a frying pan (skillet) over medium heat.
Add the curry leaves and mustard seeds.
Stir-fry for about 1 minute, or until they splutter.
Add the asafoetida, Season with salt.
Then remove from the heat and mix with ground chutney.
This chutney should be consumed on the day it is made.