Take a bowl with the atta. Add salt and mix well. Add water little by little and knead well till you get a stiff dough. The stiffness is to make sure pooris doesn't dunk more oil and not much flour is required to dust it while we roll them out.
The poori dough need not be rested as it will absorb more water after resting. Pinch into into equal size balls. Dust with flour and using a rolling pin, gently roll out discs. You should not use too much pressure as it will make the dough stick to the board and will get a dent. Roll out all the ones that are required to be fried.
Heat oil in kadai, check if its really hot. This can be done either by dropping a small piece of dough or by keeping our hands over the kadai. If you feel hot waves coming out, then it means its hot enough. Just take care not to keep it too close.
Lift the poori and dab off excess flour if any sticking to the poori. If it has extra flour, the flour will settle in the oil later, which needs to be avoided. Then slide it gently into the oil. When you slide it from one edge, oil will not splash. Gently press the poori with the slotted spoon, this way it will get cooked evenly and it will rise. Then immediately roll over the other side. Cooking this side will take few seconds more as this is the thicker side.
When its done, just keep it resting on the kadai side so that excess oil will drain away. Remove on to a kitchen towel.