Take quinoa in a bowl, wash thoroughly and add 1 cup of water and take urad dal and methi seeds in a separate bowl, wash and add 1.5 cups of water. Soak overnight or 4 to 5 hours.
Grind soaked urad dal along with water to a fine consistency. transfer this to a big bowl
Transfer some water to a cup from soaked quinoa, and grind it to a coarse consistency, transfer this to the urad dal batter
This should be the consistency
Consistency of the idli batter should like regular idli batter. Please watch for the perfect consistency. add water accordingly to grind quinoa and dal
Mix it well, cover it and keep aside for 8 to 10 hours to ferment the batter
Next day - mix the well fermented batter, add salt and mix it well again.
Now the Idli batter is ready. You can make the idlis with this batter or you can give seasoning and make Idlis.
My recommendation - adding the seasoning enhances the taste of this idli.