Soak raw rice for about 6 hrs in water and clean it. Also soak aval in curd with some water for 3 hrs. Grind them all together and add salt. Allow it to ferment overnight.
COOKING:
Add water according to dosa consistency and pour on dosa tawa little thicker than regular dosa.
Recipe by Sashi Recipes at https://www.sashirecipes.com/aval-dosai-poha-dosa-flattened-rice-dosa.html