Skin and clean the chicken, and cut into pieces. wash and set aside, let the excess water drain out of it.

In a small grinder, grind together the ginger, garlic, black pepper and vinegar to a paste (add a little water if required)

In a glass bowl, place the chicken pieces. then add the ground paste and mix well to coat (its best to do this by hand)

Add the yogurt to the chicken, and mix thoroughly by hand. leave to marinate for about 45 minutes.

In a non-stick kadhai, heat the oil. add the mustard seeds and let them splutter.

Add the finely sliced onion and green chillies to the kadhai, and saute till the onion turns translucent.

Add the turmeric powder and mix well.

Add the chopped tomatoes, along with a dash of salt. (this will help to sweat the tomatoes down quickly)

Whne the tomatoes release their juices, add the red chilli powder and coriander powder. roast this 'masala base' well for about 5 minutes, till the powdered spices lose their raw smell and take on a deep brownish colour.

Add the marinated chicken pieces, and stir gently but thoroughly to ensure that the masala coats the chicken pieces well. the chicken should turn a whitish colour.

Add a little water to the kadhai (about 1/2 cup). bring to the boil, then cover and simmer gently for about 10 minutes.

Check for seasoning, and add salt at this stage. cook for a further 2 minutes.

Add the chopped coriander, stir and turn off the heat.

Transfer to a serving dish, and serve hot with rice or rotis and a 'kachumber' salad on the side.