How to Make It
In a food processor, chop the onions. Add the garlic and ginger and process until they are finely chopped.
In a medium, enameled cast-iron casserole, heat the vegetable oil. Add the coriander, cumin, cayenne, cinnamon, cloves and cardamom and cook over low heat until fragrant, about 1 minute. Add the onion mixture and cook over high heat, stirring occasionally, until the mixture is golden brown, about 6 minutes. Add the turmeric and tomato sauce and simmer over moderately high heat, stirring occasionally, until slightly thickened, about 3 minutes.
Season the chicken breasts with salt and add them to the casserole. Coat the chicken with the sauce. Add the water, cover and bring to a boil. Simmer over low heat, turning a few times, until the chicken is white throughout, about 10 minutes. Season the chicken curry with salt.
Transfer the chicken and sauce to a serving bowl. Sprinkle garam masala on top, garnish with the cilantro and serve.
Basmati rice or naan.