Soak the dal and both the rices for 5 to 6 hours along with methi seeds
Grind the dal-rice mixture till we get a fine, thick and fluffy paste
Add salt and keep overnight in a warm place to ferment.
The next day morning add soda (as mentioned in the ingredients) and water to make batter to prepare idli (need not be very thick like rawa idli batter)
Ingredients: 3 & 1/2cups - boiled rice
1/2 cup - raw rice
1 cup - urad dal (dehusked)
1/4 tsp - methi seeds
salt
baking soda (2 pinches for every 1/5th quantity of prepared batter)