Heat skillet(tawa) and put the leftover chapatis on it. Let the chapatis become crisp. Flip over the chapatis in between. Once done, using knife or kitchen scissors cut each chapati vertically in to 1" strips. Then cut each strip in to squares. Keep them aside till use.
Pressure cook chana lentils in half cup water for 3 whistles. Once pressure is released completely, remove the lid and set aside the cooked lentils.
In seasoning pan add ghee and fry cashews, raisins one after the other. Keep them aside till use.
Method
Add fresh grated coconut in to mixer with 1/2 cup water and grind it in to fine paste. Pour this paste on to strainer and squeeze to extract thick coconut milk(first extracted coconut milk). Add squeezed coconut paste in to mixer with half cup water and again grind to fine paste. Transfer on to strainer and extract this coconut milk on to different container.
Now take the cooking pan/vessel, add second extracted coconut milk and jaggery in to it. Cook it in medium flame till the jaggery dissolves and the syrup becomes little thick.
Include cooked chana dal and left over chapati pieces. Cook for 3 minutes so that lentil and chapati pieces absorb jaggery well.
At the end add first extracted coconut milk, cardamom powder and ghee fried cashew and raisins. Bring it to boil and switch off.
Leftover chapati payasam/kheer is ready.
Notes
After including chapati pieces, do not cook for long. The pieces will become mushy.
Add water as per your preferred consistency of payasam. For me two cups of coconut milk was sufficient.
You can replace chana dal by moong dal(green gram lentil) too. If you are using moong dal, pressure cook only for 2 whistles.
Cooking leftover chapatis on tawa to make it crisp is mandatory. Do not skip that step.