Grind rice and dal together to a thin paste. Add salt. Now batter is ready for dosa cover.
For filling, heat oil in pan.
Add mustard seeds, curry leaves, and urad dal. Then add diced tomatoes. Cook it for a while.
Add diced potatoes, salt, dhania powder and chili powder.
Let the potatoes be red.
Finally, put lemon juice to it.
Now heat a non-stick pan (tawa).
Sprinkle some water over it.
Put the dosa batter with a large spoon.
Spread it making a round shape gently but quickly. It will come out on its own from the tawa surface when done.
Fill potato filling in it or serve separately.
Serve with tomato, coconut, and peanut chutney.