First cut the left over chapatis in dimond/square shape and keep it aside.

Now put kadhai on flame and add oil and heat it up. Once oil gets heated add mustard and cumin seeds and let them crackel.

Now add onion, green chillies and curry leaves and saute it till onion changes it's colour to slightly golden.

Now add ginger garlic paste and saute it for about 1-2 min. Now add tomato, chilli powder, turmeric powder, salt to taste, garam masala and Coriander powder and mix them all well.

When tomato gets cooked add water and let it boil. When water gets boil add besan and mix it well make sure no lumb should form. (Or make besan water paste and add it to boiling water)