In a food processor, chop the onions. Add the garlic and ginger and process until they are finely chopped.

Heat the oil in a pan. Add the coriander, cumin, peppercorns, cinnamon, cloves and cardamom and cook over low heat until fragrant. Add the onion mixture and cook over high heat, stirring occasionally, until the mixture is golden brown.

Add the turmeric and tomato puree and simmer over moderately high heat until slightly thickened.

Marinate the chicken with salt and add it to the gravy. Coat the chicken with the gravy. Add the water, cover and bring it to boil.

Season the chicken curry with garam masala.