Add cooked rice, rice flour, wheat flour/atta and curd to a mixer.
Add some water and blent it smooth.
Transfer it to a bowl. Add salt and baking soda to it. Mix well.
Add water(if required), to maintain the consistency of the batter. It should be of dosa batter consistency.
Heat a pan/tawa and rub some oil using sliced onion.
Sprinkle some water on it to reduce the temperature.
Now spread the dosa batter on the tawa. Thin layer.
Add some oil. Cover it using a lid and cook.
When done, remove the lid and take out the dosa using the spatula. Fold it and serve hot with chutney and sambhar.