Make slightly smaller balls from the dough, about ping pong ball sized. Flatten a ball, rub a little oil onto the board (this is better than sprinkling flour, as they are going to be deep fried, and flour would muck up the oil quicker)and roll out into a roughly 4 inch circle, again ensuring the edges are thin. It is best to have a sort of assembly line for making puris, one person rolling them out and another frying them as you go. If you are alone, might be good to roll out a couple in advance, (don't pile them up - they will stick to each other) but then fry one, roll another one, one at a time.
When the oil is really hot (but not smoking), slide in the rolled disk into the oil, and stand ready with a flat hole-y spatula. As the puri starts to rise (in maybe 5 to 10 seconds), hold it down with the spatula; it will star to resist and struggle to bob up, puffing out as it does so. Hold it down for maybe fifteen seconds until golden brown on that side then turn over and hold down on the other side. You should have a beautiful golden puffed out ball. Line a colander with kitchen towel and pile up the puris until ready to eat. They are fine to eat at room temperature, don't need to be hot.