Roughly chop your onion, garlic, chilli and ginger.
Using a food processor, blend to form a paste.
Heat your butter or vegetable oil and add the paste. Cook over a low heat for 5 minutes.
Add the spices and cook for one minute more until fragrant.
Stir in the tin of tomatoes and half a tin of water.
Simmer for 5 minutes until the sauce starts to thicken.
Drain the chickpeas and add to the sauce.
Cook for ten minutes more.
Stir in the coriander and serve immediately with rice.