In a mixing bowl add rawa,rice flour,salt,curd and mix well.Add in water as per needed and mix well.This should be a medium consistency batter(Not so thick,Not so thin).Set this aside for 15 min.
Heat oil in a kadai and add in mustard and cumin seeds and let it crackle.Add in ginger and curry leaves.
Add in onion,carrots,beans and mix well.Let it cook for 3 min.
Add this to the batter and mix well.Add in lots of coriander leaves and mix well.
Add in baking soda and beat well till it gets foamy and mixed in.
Add a tblspn of the batter into well oiled idli stand or any small bowls and steam it for 10 mins?
When it is cooked,remove it with a spoon and place it in a insulated box.
Serve hot with any chutney or sambar...