Method:

1. Soak black channa overnight and pressure cook for 6-7 whistles or until soft.Dont drain water, set aside.In a pressure cooker heat oil add tomatoes and onions, fry till mushy and raw smell of toamtoes leave.Then add red chilli powder, coriander powder and garam masala powders.
2. Fry till raw smell of spice powders leave, add required salt then add channa along with water and pressure cook for 1 whistle(this step is purely optional) - but I recommend doing so as it makes the channa soft and blend with the masalas well. Heat a pan and add the ingredients listed under 'to roast & grind'.
3. Roast till nicely browned to a darker shade.Then transfer it to a mixer,add little water and grind to a smooth paste.
4. Add the paste to the gravy (add water it its too thick)and let it boil for 3mins. Then heat oil in a tadka pan - add the items listed under 'to temper' let it splutter.Fry till onions turn golden brown.
5. Add the tadka to the gravy  - I transferred it to the pan at this stage as I needed my pressure cooker for making the puttu :). Adjust salt....Allow it to boil till the curry thickens to the desired consistency.Switch it off.

My Notes:

• Make sure you dry roast the ingredients listed to nice dark brown.
• You can even skip small onion while tempering.
• Pressure cooking chana along with the masala gives a great blend and flavour too.But if you dont prefer pressure cooking then allow it  to boil for 5mins then go to the next step.
• Adding coconut milk at the final stage gives a great flavour.
• Instead of garam masala you can even roast and grind whole spices(cinnamon,cloves,cardamom) along with coconut.