Heat oil in pan add cumin seeds and allow to sputter. Add chopped green chillies, onion and fry till onion get cooked. Now add the tomatos and saute it for a while. Add the chopped mushroom and cover it and cook. Let it cook for 5mins. After 5 mins add all the powdder masalas and if necessary add some water and cook until the raw smell gone. Finally add some coriander leaves and remove from the fire.
Pour a ladle of batter on the Dosa tawa, spread it and add oil on the sides. After a few minutes turn it on to the other side. When done , Turn again and spread mushroom masala on one side. Bring the other side of dosa up and close the stuffing. Cook for one minute and serve with chutney.