Jowar is known as vellai cholam & also called big millet.
The photo of the grain is given below. This dosai can be made with minimum oil & is a soft type of dosai. It is best not to make it very thin. Once the batter is spread, dribble just ½ tsp oil over it, cover & cook. Turn over & cook for just a few secs. Serve with sambar or any chutney.
Jowar - 2 ½ cups
Par boiled rice ( idli rice) - 2 ½ cups
Urad dhal - 1 cup
Salt
Oil
Mix jowar, rice & urad & wash well.
Soak in enough water for 6-8 hrs.
Grind to a fine batter adding water as for usual dosai.
Add salt & ferment the batter for 10 hrs .
Make dosas as given above.