In separate bowls take idli rava and urad dal (split black gram).

Wash the urad dal for 2-3 times in water. Soak the urad dal. Add 1 tsp of fenugreek seeds (methi dana) to it. In another bowl soak idli rava with the water. The water should just soak the idli rava with a thin layer on top. Cover and let them soak for 4-5 hours.

Drain the water from soaked urad dal. In a mixer, jar put the drained urad dal and fenugreek seeds. Churn them together. Add very little water and again blend them till smooth.

Remove the smooth ground urad dal and fenugreek seeds in the big bowl.

With the soaked idli rava, squeeze water from the rava by putting in fist. Make balls and remove half the quantity of squeezed rava in the bowl of ground urad dal.

Grind the remaining half rava with some water to a semi coarse paste.

Add the semi coarse paste to the ground urad dal, squeezed idli rava ball in the bowl.

Mix them together with hands in circular motio till they are blended well. The heat generated with hands aids the fermentation process.

Cover the bowl and keep it in warm place to ferment for 6-8 hours. I usually put it in the microwave or oven. (for microwave, place a glass of water and heat it for 1-2 minutes on high, remove the glass and keep the bowl with batter in the microwave to ferment. for oven, preheat the oven at 100 C and then after sometimes place the bowl with batter to ferment) Doing this way makes sure that the oven or microwave are warm enough to put the batter for fermenting. This helps in the cold winter days. In summer you can simply put the bowl without pre-heating. If you get sunlight in your house, place the covered batter in it for sometime. This will also help for fermentation.

After 6-8 hours the batter is rise and it has got nice fermentation.

Mix well.

Remove in the small bowl the quantity of batter needed to make idli. The rest batter can be used to make dosa or uttapam or freeze it and use for next time. Add salt and around 1/4 th cup of water to the batter to make it thin.

Grease the idli stand with oil.

Pour the batter into the greased stands. Place the idli stand in the vessel filled with water. Cover the vessel with lid so that the steam is not able to escape. Cook the idli for 8-1o minutes.

Remove the idli. let them cool. If you want you can brush idli surface with oil.

Remove idlis with small spoon or knife. similarly make remaining idlis.

Serve it hot with sambhar and chutney.