Sift the kuttu atta in a big bowl.
Add boiled mashed potatoes in the kuttu flour.
Add finely chopped green chilies in it. (it is optional, if you want little spice in puris then add it)
Add 2 tablespoon oil in it
Add finely chopped coriander leaves in it
Add black pepper powder in it.
Add rock salt (sendha namak) according to your taste in it.
Mix all the ingredients first in it.
Add slowly little water in it and knead it. And make it a soft dough.
The soft dough is ready.
Cover it with cloth or plate and leave it for 10 minutes.