Chicken tikka with tomato

For the marinade:

5 tablespoons olive oil

3½ tablespoon red wine vinegar

1 onion, chopped

4 garlic cloves, chopped

2.5 cm (1 in) piece of fresh root ginger, chopped

2 tablespoons ground cumin

2 teaspoons ground coriander seeds from 10 cardamom pods

1 teaspoon ground cinnamon

8 cloves

20 black peppercorns

1 teaspoon cayenne pepper

2 teaspoons slat

1 tablespoon tomato puree

1.5 kg (3lb) skinned and boned chicken breasts

Put all the ingredients for the marinade in a food process to a smooth paste.  Cut the chicken breasts into strips 5 cm (2in) long and 1 cm (½ in) wide.  Put the chicken pieces in a bowl, add the marinade and stir to mix. Cover and chill for 4-5 hours. 

Preheat the grill and line the grill pan with foil. Arrange about half the chicken on the foil in a single layer, leaving behind any marinade that does not cling to the meat. Grill the chicken for about 10 minutes or until there are light-brown spots on the surface.  Turn over the chicken pieces and grill for another 10 minutes, until lightly speckled.  Transfer to a warm plate and cook the remaining chicken in the same way.  Serve immediately.