Pottukadalai Sambar

Grind the roasted split gram/pottukadalai into a fine powder
Mix the above ground powder with water and make it to a thin fine solution.
A ratio of 3 to 4 times of water to the above powder is a good approximation.
In a kadai, heat oil and add hing and mustard seeds.
Once it starts spluttering add urad dal followed by green chillie and curry leaves.
Then add shallots, once the shallots become translucent add the chopped tomato.
Once the tomato becomes mushy add the sambar powder
Then add the prepared solution followed by tamarind concentrate.
Add salt to your taste needs.
Allow it to boil until the raw smell of pottukadalai goes away (it took around 15 mnts for me in medium flame).
Stir the mixture to prevent formation of lumps.
Stirring also helps in avoiding stickiness at the bottom.
If it becomes more thick u can add water as needed.