Heat oil in a pan and temper with mustard seeds and whole red chili. After it stops spluttering add the curry leaves, asafoetida, urad dal and chana dal. Saute for a few seconds.
Add the sooji and poha. Stir fry on a medium flame for 2-3 minutes or till you get a nice aroma. Set aside to cool down.
Add the yoghurt, green chilies, coriander leaves, idli podi, asafoetida (opt), salt and 2 cups water. Mix well and set aside for 25-30 minutes.
Add more water to have a batter like consistency. Just before steaming, add the eno fruit salt and stir well.
Pour into the greased idli moulds and steam for 12-15 minutes. Demould when it cools down a little. Serve with coconut chutney and sambar.