Wash the raw rice, black gram, finger millet, pearl millet and fenugreek seed in cold water 2-3 times.
Soak this with water to completely immerse. Add more water if the water is completely absorbed after some time.
Cover and let it soak for 6-8 hours.
After 8 hours, grind the soaked rice, black gram,millets and fenugreek seed with cooked rice and water. Use the same water used for soaking to make a smooth, free-flowing and medium-thick batter. Do this in batches.
Transfer the batter to a large vessel. Mix well with a spoon or ladle. Cover and let it ferment in a warm place, preferably in the oven during cold conditions.
The batter will ferment and rise. Add salt to the fermented batter and mix well. You can refrigerate the batter at this point until you wish to make dosa.
Heat an iron griddle or non-stick pan on medium heat.If using a griddle, brush it with a little ghee or oil. Pour a ladle of batter into the griddle. With the back of the ladle, spread the batter spirally outwards starting from the middle to make a thin crepe (dosa).
Cover and cook until the bottom of the crepe begins to brown. Spread a tsp of ghee over the dosa.
Transfer to a plate. Repeat with the remaining batter. Serve and enjoy hot with chutney or Sambar.
Notes
Any cooked rice can be used. Cooked rice makes the dosa more soft.
You can use any grains to make the crepes.
Since the soaked water is fermented, using the same water for making batter speed up the fermentation.
Add more water if necessary to make the right consistency of the batter. See the video.
Adding a little sugar helps the fermentation process which is optional.
In extreme cold conditions, place the batter in the oven to help the fermentation. Preheat the oven for 5 minutes. Switch off the oven and place the batter inside.
For better fermentation, do not cover the vessel completely. Leave a little breathing way for the air-flow.