Prepare the Idli Dosa Batter as mentioned in the recipe here.
Once the batter is well fermented you are ready to prepare the uttapam.
In a large bowl add in the Idli Dosa batter. Adjust the consistency of the batter using water.
The batter consistency should not be thin or very thick. Something like dropping consistency. I.e. semi-thick.
Heat a Dosa tawa or a skillet or a crepe pan. Grease it with oil using a pastry brush or half cut potato or simply a clean kitchen tissue.
Pour a ladle full of batter on the skillet. If the consistency is right it will spread on its own. You would not need to spread it. If not just make a circle outwards with the back of a spoon.
It should not be thin but slightly thick.
You would see small pores appearing on the top when you pour the batter.
Top it with 1 tablespoon of chopped onion, a few chopped pieces of green chilly and a few coriander leaves.
Cover and let it cook on slow to medium for 4-5 minutes or until the bottom is done.
Drizzle a teaspoon of oil along the edges and slightly on the top.
Flip and let it cook on the bottom as well for 2-3 minutes.
Serve it hot with Chutney, Sambar or Podi.