First soak the semolina for 10 minutes...

Heat oil in a pan, add mustard seeds and cumin seeds and saute them... Add chopped onion and curry leaves and saute them well...

Add the fried onions, semolina and salt to the leftover dosa batter, add required amount of water and mix well.

Heat a cast iron pan. When the pan becomes hot, spread ¼ to ½ teaspoon oil all over the pan.
Do keep the heat on low to low-medium heat, so that you are easily able to spread the batter. If the pan base is very thick, then keep the flame to medium.

Pour a ladle full of batter and slightly spread it. No need to make thin,make like pancake. Drizzle few drops of oil.Flip and cook both sides.

Now ready to serve with chutney..