Wash and soak the Urad dal and Fenugreek seeds together in ample water for 4-6 hours.
2
Wash and soak the Idli rice separately in ample water for 4-6 hours.
3
Drain the soaked Urad dal and Fenugreek seeds. Grind them in a wet grinder or high-powered blender, adding cold water gradually, until a very smooth, light, and fluffy batter is formed. This may take 20-30 minutes in a wet grinder.