Put the ghee in a kadai and fry rawa till its raw smell goes. Remove it and cool. When it is cool, add curd (beaten well), salt and soda and mix well. The mixture should be like thick idli batter. No need to add water. Curd is enough. In a kadai pour oil and when it is hot add mustard. When it pops up, add Bengal gram dhal, urad dhal, cashew nuts and asafetida and fry for a few seconds. Add the chopped green chilli, ginger and curry leaves fry for a few seconds. Add this to the rawa mixture. Mix well. Grease idli plate. Put little carrot gratings and pour idli batter over this. Make idlies and steam for 12 to 15 minutes. Make sure the water boils well before keeping the idli stand in the idli cooker.