Soak rice and urad dal for at least 6 hours.
Wash it thoroughly and add aval /flattened rice flakes to it.
Grind it in a wet grinder or mixer with required water.
The batter should be grounded till smooth.Last add required salt.
Remove the batter to a bowl .Reserve one or two tablespoon batter.
Add approximately 1/2 cup of water to the reserved batter and remove it in another pot.
Heat the batter and water mixture in medium flame continuously stirring.
It will become a thick glue like consistency.
When it cools down,add it to the batter in the bowl.
Cover it and let it ferment overnight or at least 8 hours.
The batter is ready for making delicious appams.