For batter : Mix wheat flour, rice flour, green gram and black gram powder, some salt and make a thick paste. Set aside for a while.
For masala: Heat oil in a pan and add mustard seeds.
Add curry leaves, chilly, ginger and onions.
Add salt, turmeric powder and saute for a minute.
Roughly mash potato and add it into the pan and cook for 3-4 minutes.
For uttapam: Heat non stick tawa and grease it with oil.
Pour the batter and make uttapam from circumference to the centre.
Take some potato masala and spread it on the uttapam.
Flip it and cook on the other side too by adding little oil on the sides.
When it is cooked remove it on a serving plate and enjoy with coconut chutney.