Slightly roast semolina in a pan and leave for 5 minutes for cool.
Add curd and salt and mix well and make the batter with 1 cup water.

Batter consistency is medium. Keep aside for 10 minutes.
Heat the oil in a small non-stick pan, add mustard seeds, split black lentils, asafoetida, green chillies,

Curry leaves, and ginger paste and saute on medium flame for one minute.Add this tempering in the prepare semolina batter and mix well.

Now add chopped coriander leaves and mix well.Now divide this batter into three parts to make tri coloured idli.For orange batter add orange colour and tomato sauce in one part

For green batter add green colour and green coriander chutney in the second part and leave as it is the third part.
Just before steaming, add fruit salt and mix gently.

Just before steaming, add fruit salt and mix gently.
Pour 1 teaspoon of the batter into each greased idli mould and steamed in a steamer for 8 to 10 minutes.
Cool slightly and remove from mould and serve with sambhar and chutney.