Heat a large pot over medium heat. Add oil and red onion and cook, stirring frequently until it is caramelized.
Reduce the heat to low. Add garlic, cumin seeds, coriander, ginger, garam masala and cardamom pod, stirring constantly, until the cumin seeds pop and the spices are fragrant and toasty, about 30 seconds.
Pour in the tomatoes and mash. Add potatoes. Raise the heat to medium-high, and bring to a boil.
Reduce the heat to medium, add the cilantro and cayenne, and all of the rest of the spices, and simmer until it begins to thicken.
Add the chickpeas, and stir to combine. Simmer 30 minutes.
Serve over brown rice or quinoa and garnish with cilantro.