Mix all the ingredients listed for the dough and make it into soft dough. Cover the dough and let it rest for at least 30 mins. The longer the dough sits, the easier it stretches when making the poli. I generally do this as the first step and let the dough rest for couple of hours.
Take a piece of banana leaf (In my case I used Aluminum foil) and apply some oil in the surface. Take a small piece of the dough and spread it with your fingers.
Now place the round filling inside it and close it with the dough all around and pinch the seams.
With the heel of your palm, slowly apply pressure to the poli and make it even and bigger. Take care that you do not press it too hard to make the filling come out. Also try not to use your fingers much as that leaves impression on the poli and it will not appear smooth.
In the meantime, heat a non stick or a cast iron tawa/griddle on medium high heat. Once the poli is spread, transfer the poli with the aluminum foil (or banana leaf) on to the tawa, face side down.
Wait for about 30 secs and then slowly peel the foil from the poli. Apply oil and cook the poli on both the sides until golden brown.
Repeat the same procedure with the rest of the poli. I usually have 2 sets of foil and work on the other when one is cooking, so I always have one ready to go.
Serve warm with ghee!