In a pot over medium heat, combine the first 5 ingredients and cook until reduced to a thick syrup. Reserve until the aubergines have been cooked.
To cook the aubergines, place them on a hot fire or in coals until soft and blackened. Alternatively, grill in the oven or roast at 230°C to achieve the same result. The skin should be crisp and literally charcoal. Remove from the grill and t