Daal and rice with some water and soak it overnight. Next day make a smooth paste add some water and make a medium thick batter. And cover it and keep it in a warm place for 15-18 hrs.

Heat oil add curry leaf and mastered add onion and salt, Turmeric. Fry it and add smashed potato mix it well and cook it for 5-10 minutes.

Take a iron pan and sprinkle some water on it and keep the flame low and took one small bowl of batter and spread it all over the pan.. add some oil until its turned into golden brown then add potato masala and fold it and dosa is ready.