In a large pan, heat the oil over medium heat. Reduce the heat to medium-low and add the cumin seeds. Stir and toast the seeds for a minute or two until golden.
Raise the heat to medium and stir in the onion, garlic and ginger. Cook for a few minutes then stir in the garam masala, coriander, turmeric, salt, and cayenne and cook for 2 minutes more.
Add the diced tomatoes and their juices.
Raise the heat to medium-high and add the chickpeas. Bring the mixture to a simmer and cook for 10 minutes or longer.
Serve over a bed of kale and cooked rice, if desired, and garnish with some chopped cilantro just before serving.
Tips: To thicken the tomato gravy, add a ladle of the curry into a mini processor and process until almost smooth. Stir this back into the curry to thicken.