In a mixing bowl, mix together the rava (semolina), salt and yoghurt. Keep this aside to rest for 30 minutes
Heat a small frying pan and add the mustard seeds and urad dal, when the seeds crackle and dal browns, add the curry leaves and cashews. Cook for 2 minutes and add in the carrot, chilis and turmeric powder
Stir fry for about 5-7 minutes and remove from heat and add it into the rava and yoghurt batter. Add a cup of water and mix uniformly
Add the fruit salt (I have used Eno), mix well another time. Grease your idli moulds with ghee/oil and fill each of them with 2-3 tbsp of the batter. Steam on medium high heat for about 10-12 minutes or until a toothpick inserted in the centre of a idli comes out clean
Serve your delicious instant rava idlis hot along with a chutney of your choice. Enjoy!