Although they use the same dough as chapatis, pooris are smaller and more puffy because they are fried in hot oil rather than on a dry griddle. The dough for pooris can be enriched with the addition of 1 tbsp melted ghee or butter, if you like.
Heat 5 cm vegetable oil in a deep frying pan until hot. Add one poori and cook for about 10 seconds until it puffs up. Flip it over and press down with a spoon, then cook for 10 seconds until puffed up and golden. Drain well and serve at once.