Strain the water. Reserve this water for making Aamati (curry).
Take a thick bottom vessel or kadhai. Add jaggery and the boiled dal. Mix continuously so that dal doesn't stick to the bottom.
Now using a hand blender, blend the dal jaggery mixture to get a smooth and fine puran.

Now take a large bowl. Add dry flour, salt and Turmeric to it. Heat 3 Tablespoon oil in a pan. Once cooled slightly,but warm, add to the flour and mix well. Add water little at a time and knead a soft dough. Add 2-3 tablespoon more oil and keep kneading the dough. Cover and keep aside for 10 minutes.

Now take a lemon size dough ball. Shape it into a bowl. Add puran (double the size of the dough ball).close the edges and start rolling like a paratha. Use dry flour in between if required.
Flatten from all sides.
Heat a tawa and cook the puran poli from both the sides. Apply some oil while cooking.
*This will help to keep the polis soft for a longer time.

Serve these puran Polis with ghee and milk or katachi aamati.