Heat oven to 180C/160C fan/gas 4. Put the chicken in a roasting tin, season well and cook for 40 mins or until cooked through. Either carry on with the recipe or cool and chill. This step can be done up to two days ahead.
Put the sauce ingredients in a pan and bring to a simmer, then keep cooking until it thickens a little and looks shiny. Use straight away or cool and chill. The sauce will keep for a week in the fridge.
Heat a barbecue until the coals are glowing white hot. Brush the chicken pieces all over with the sauce and barbecue them on each side until they are browned and sticky, then brush once more with the sauce. Don’t worry about cooking them through, as they are already cooked. If you want to cook them indoors, coat them in the sauce and grill on a medium heat on all sides.