To begin the curry first you need to heat the oil in a large pan.
Once hot but not smoking, add the lightly crushed mustard seeds, cook for 30 seconds only, beware they may pop and spit out of the pan.
Add the chopped onion, lower the heat and cook for approx 3 - 5 minutes until soft but not coloured.
Then, add all the spices plus the garlic and ginger. Cook on a medium heat taking care to ensure the spices don''t burn.
Add the chicken, the sugar stirring well to make sure all the chicken is coated in the spices.
Cook for 10 minutes stirring occasionally to make sure the chicken or spices are not burning.
Finally, add the stock, the tomato purée, a samll pinch of salt and the bay leaf. Stir again and then lower the heat.
Cook gently for 25 minutes until the chicken is cooked through and tender.
Finally add the cilantro/coriander and tomato, stir and cook for a further 3 minutes.
Serve piping hot in balti dishes with naan breads on the side.