In a mixing bowl, add besan, turmeric powder, salt, red chilli flakes, ajwain and required or 1.25 cup water to make a medium thick batter.

Whisk the batter in one direction so air incorporates into the batter and makes a soft and fluffy pudla.

Cover and rest batter for 15-20 minutes.

In a pan, add oil, jeera, ginger-garlic paste and green chilli paste. Sauté for a minute.

Add onion and cook till onion becomes translucent.

Lower the flame and add turmeric powder, red chilli powder, coriander powder and cumin powder. Mix well.

Now add boiled and mashed potatoes and salt. Mix well.

Then add garam masala, black salt, lemon juice and coriander leaves. Mix well.

The potato stuffing is ready.

Cool down the mixture completely and make round and slightly thin tikki from the stuffing. Keep it aside.

Heat the tawa, grease with oil and lower the flame.

add chilla batter and spread it slightly in a circular motion.

Add oil to the sides of chilla and cook it evenly from both sides.

Then place potato stuffing tikki in the center of chilla.

Cover the tikki with besan batter.

Flip it. Cover and cook it on medium-low flame till it is slightly golden brown from both sides.

Serve besan chilla sandwich with tomato ketchup or green chutney.