Drain the chickpeas. Rinse them gently with fresh water. Drain again. Put the oil in a wide pan and set over medium-high Now put in the cumin seeds and let them sizzle for about 15 seconds. Put in the onion. Stir and fry until the onion turns quite brown at the edges. Put in the garlic and let it turn golden, stirring as this happens. Now put in the tomatoes. Stir and cook them until they turn dark and thick. Add the ginger and give a few good stirs. Now put in the chickpeas and all the ingredients. Bring to a simmer. Turn the heat to low and simmer, uncovered, for about 10 minutes, stirring gently now and then. Cook until desired consistency.
Taste for balance of flavors and make necessary adjustments.