Wash the dal and soak it for 2 hours. After 2 hours strain the water and grind the dal without water in a mixer.
Sieve the flour in a bowl and mix salt and oil in it. Knead the flour with water to make a smooth dough. leave the dough for half an hour to set.
Heat oil in a small pan and tamper the heeng and cumin seeds into it. Put the coriander powder once the cumin seeds is roasted well and turns brown. Now add salt, red chilli powder and dal into the pan and mix well with the masala. Roast the dal with spoon for 5-6 minutes. The filling to stuff the poori is ready.
Heat oil in a broad pan to fry the pooris. Let the oil heat up. Meanwhile, make small ball of the dough. Pick one ball and spread it with hands making a small dent at the center. Stuff the dent with 1/2 tea spoon filling and close it. Now roll out the poori into a flat disc of 3-4 inches and put it inside the pan to fry. Fry the poori till it turns brown in colour. Take it out on a plate and prepare more pooris in the same manner.
Serve the hot Dal Stuffed Poori with matar paneer, chutney, raita and pickle.