Note 2: For a rich gravy you can also add 2-3 cashewnuts to the onions and then grind.
Note 3: For a typical restaurant like taste, you can use the Dhungar method to add a smoky flavour to the gravy. Heat a piece of charcoal directly on flame. Place it on a piece of aluminium foil and place this on the gravy. Immediately drizzle some ghee on the charcoal and put a lid on the vessel for some time.Remove the charcoal & the foil.