Wash and soak kambu for minimum 3 hours or overnight.
Drain, spread over a clean cotton towel for the excess water to get absorbed.
Once the extra moisture is absorbed, transfer to a blender and powder it coarsely.
Heat a pan with oil and temper with mustard, urad dal and asafoetida followed by curry leaves.
Add ginger, green chilli, followed by coriander leaves and coconut.
Stir well for a minute until coriander leaves shrink and add 1 & ½ cups water along with salt. Bring to boil.
Put in medium flame and add the powdered bajra.
Stir briskly and cook covered in medium or low flame for 4 minutes.
Set aside covered for cooling down. Once warm enough to handle, grease your hands with oil.
Make oblong shapes with the dough prepared, using your hands as shown in the picture.
You can make round balls too, but this is easy to get steamed.
Arrange in greased idli plate/ steamer and steam cook for 10 minutes.