Boil the potatoes and keep it aside.heat oil in a pan, crackle mustard seeds, jeera, curry leaves and hing.now add ginger garlic paste or chopped ginger garlic and mix well.
Add chopped chillies and chopped onions and fry until they turn pinkish in color.once the onions have changed the color, add turmeric and mix it properly.
Add chopped coriander leaves to it and mix properly. the masala will be hot so aloow them to cool little.make small balls out of the mixture and flatten them as a patties and keep aside.
In a large bowl, add 2 cup of roasted rava. using rava without roasting makes your idli slightly sticky.to that add 1 cup of curd or yoghurt. it is best to use slightly sour curd. however it is not compulsory.
Add water and mix it well.Bring the batter to idli batter consistency by adding water if required keep the batter to soak for 30 minutes.after 30 minutes add of baking soda and give a stir. you can now see the batter turning slightly frothy. do not mix more.
Grease the oil steel glasses and switch on the steamer with enough water.pour 1 tbsp of idli batter into each impression place the flattened potato stuffing gently press the aloo stuffing.
Gently press the aloo stuffing.pour again 1 tbsp idli batter to cover the filling.stack up all the idli glasses and steam for 10-12 mins. rest it for another 3-4 mins.
Fry the idli unmould the idli plate and serve hot with chutney.
