Coarsely grind the fresh garbanzo beans and keep aside .
Heat the mustard oil till it smokes . Switch off the gas and let the oil cool .
Switch on the flame , heat the oil again , add the potato cubes .
Add a pinch of salt .
Fry the cubes till tender and cooked .
Remove with a slotted spoon and keep aside .
Using the same pan and leftover oil add cumin seeds and asafoetida .
Immediately add turmeric powder and coriander powder .
Now add the tomato purée and chilly ginger paste .
Cook till oil separates.
Now add the coarsely ground green channa .
Add salt and mix well .
Let cook till the raw smell of channa is gone .
Add water according to the consistency you want .
Just before serving add the fried potatoes , garam masala and coriander leaves .