If the puris do not puff up, then it could mean a couple of things. Either the dough has not been kneaded well, the puris have not been rolled out evenly or the oil is not hot enough. Knead the dough a bit more. Oil your hands when kneading. Ensure you roll out the puri evenly. The thickness of the poori is important in this recipe. It should be even all through. A too-thin or thick poori might not puff up and will also soak up too much oil when deep-frying. Always check if the oil is hot before adding the puri by dipping a mustard-sized ball into the oil. If it rises up immediately, it means it's hot. If it sinks to the bottom means it's not yet hot.