Soak green moong dal and white urad dal overnight. Next morning, wash the dals thoroughly and drain all the excess water.
Tranfer the dals in a mixer jar alongwith green chilli, ginger and salt. Add about ¼ cup water and blend. Gradually add water. We required about ½ cup water in total. Keep blending and adding water.
Once it gets blended well, transfer to a bowl. Add besan and mix well till no lumps remain. Chilla batter is ready.
For the stuffing
Heat oil in a non-stick pan. Add cumin seeds and hing. Now add chopped carrots. Stir, cover and cook on a low-medium flame for about 3-4 minutes.
Now add boiled corn and all the dry spice powders (chaat masala, coriander/dhaniya powder and cumin/jeera powder) and salt. Mix well.
Switch off the flame and finally add crumbled paneer and give a quick stir.
Remove from flame and keep aside.
Preparing chilla
Heat a non-stick tawa/ flat pan on medium heat. Spread a few drops of oil on tawa/pan.
Pour a spoonful of batter and spread the batter gently with the back of ladle.
Spread oil around the chilla, reduce the flame and cook till the top portion begins to look cooked.
Now flip it over and cook the other side.
Cook till both sides of the chilla turn golden brown.
Put the stuffing in the centre and fold the chillas.