Soak the rice, dal, sago, fenugreek seeds, castor beans in separate bowls for 5-8 hours/overnight.
drain the urad dal and grind it along with the fenugreek seeds.
grind with little water until smooth and thick. Take it out in a bowl.
Drain rice and de-skin the castor seeds. Grind together castor seeds, rice, and sago with water as and when needed to a thick and smooth batter.
Mix in salt and the prepared urad dal fenugreek batter.
Take everything in a bog bowl with enough space to rise.
ferment for at least 4-5 hours. Mix and take a portion of the batter and add soda to it. mix well. let it rest for 10 minutes.
After 10 minutes, mix again and pour a ladleful of batter on each pit of the idli plate that is lined with the wet cloth.
steam cook for 10 minutes or until knife inserted into idlis comes out clean.
serve it hot with side dish of your choice.