Soak the roasted gram in water for at least 20 min.
Add all the Ingredients other than the ones mentioned in the Tempering section in a blender and blend them till smooth.
In case if its too thick, add more buttermilk till its neither too thick nor too watery.
Now in a tsp of oil, temper the ingredients given in the To temper section till the mustard seeds start popping.
i made this i coulndt get roasted chana so substituted with a handful of kabuli chana soaked overnight and boiled and minced with coconut, it tasted fabulous thanks for the recipe
I have specified it what it is near the ingredient itself. Its roasted gram/dalia. I think it is also called as bhuna chana - see image here