Drain & wash chickpeas.
Chop tomato, & puree with green chilies and ginger
Heat oil in saucepan. Check if hot enough by adding 1 cumin seed; should crack right away.
Add cumin seeds. (Original calls for adding garam flour after crack & stir-frying for 1 minute; I've done without)
Add tomato puree and all other spices except garam masala, cook for about 4 minutes. Should "leave oil" and reduce in size by about 1/2.
Add chickpeas and water (enough to cover), cover, simmer/boil for 7-8 minutes.
Smush some of the chickpeas in the pot, add garam masala & cilantro, let cook about 1 minute.
Garnish with cilantro and tomato slices if desired.