Pour the besan into a bowl.
Add all the chopped vegetables, chaat masala and rock salt. (Pro tip: Avoid a lot of vegetables in the mix. They will release too much moisture and can make the chilla difficult to cook through.)
Mix well.
Add a small amount of water. Mix well.
Add more water in batches and keep mixing.
Make sure the batter gets a semi-thick consistency.
Put a non-stick pan on the gas stove.
Brush a bit of white oil on it.
Take a ladle of the batter and fry it in the pan.
Cover the pan with a lid. Cook for a few minutes on a low to medium flame.
Take off the lid. Flip the chilla. (Pro Tip: If the chilla sticks when you try to flip it, give it another minute instead of forcing it loose.)
Brush a few drops of oil. Put the lid back over the pan.
Let the chilla cook for 5 minutes on a low to medium heat. Remove it when done.
Besan chilla is ready.