Wash and soak samai arisi / little millet for 3 to 4 hours. Rinse well until water turns clear.
Similarly, wash and soak black gram / ulunthu along with fenugreek seeds separately.
When ready to grind the batter, drain and take the soaked black gram / ulunthu and grind it till smooth and fine paste.
Once the urad is very soft and airy texture, transfer the to a big vessel.
Next, grind samai by adding water little at a time to a slightly coarse paste. Consistency of batter should not be too grainy nor fine paste.
Now, mix both the batter together with required salt, mix well.
Transfer the batter to a container that has enough room for the batter to ferment.
Batter consistency should not be too thick or too thin. Ferment the batter for overnight.
Once fermented, gently mix the batter and refrigerate right away if you are not going to use.