In a bowl add boiled potatoes and mash them. The potatoes must be on room temperature.
In the mashed potatoes add all-purpose flour, sufi cooking oil, roasted and crushed cumin, salt, red chili powder, turmeric powder and fresh coriander and kneed the puri dough while gradually adding water until firm dough is formed. Leave to rest for 15 minutes.
Grease dough with oil, cover the bowl with lid and leave the dough to rest for a few minutes.
Make small dough balls and rest for maximum 4-5 minutes and then roll them out. Make sure to keep the puri thicker from the center or it would not puff up.
Now deep fry the puris in properly heated oil and while frying gently press them so that they may puff up.