Method:

Mix flour, salt, soda turmeric together with water. Knead well to make a soft dough and then add 1/4 cup oil. Cover the dough and keep aside for at least 1 hour.

Wash and drain the chana dal. Pressure cook the dal (2 whistles) and once it's done, strain the excess water.

Add jaggery and mix well. Let the jaggery melt.

When the dal is little warm add coconut and cardamom mix well (or you can also add that while grinding).

Grind to a fine paste and keep that aside.

After 1 hour knead the dough again until non-sticky and soft.
Now take a gooseberry-sized lump of the dough and a lemon-sized lump of the dal mixture.

Press the dough spread it lightly like a small poori.

Make sure the corners are thinner than the centre.Keep, the stuffing ball in the middle and cover the stuffing with the dough, pinch the edges together to seal the filling.

Dust the ball with rice flour and roll gently into flat rounds of about 8 to 10 inch in diameter.

Heat tava (griddle) apply some ghee or oil and cook the Puran Poli on over a medium heat, till it turns golden brown in colour from both the sides.

Note: Add the jaggery when dal is hot that help jaggery to melt fast. Try to grind when the dal is warm, so that food processor will run smoothly.
Excess dal water can be used to make curry, rasam or soup.