Cut the pork fillet into cubes. Heat the sugar and vinegar in a pan over a low heat until the sugar melts. Add the fish sauce and cool. Tip in the pork and mix well so that all the cubes are covered in sauce.

Heat the barbecue. If you are using coals, wait until they turn white. If you are indoors, heat a griddle pan. Thread the pork and pineapple onto skewers, alternating pieces with the pepper and spring onion.

Barbecue or griddle the skewers for 3-4 mins each side (you may need to cook them for longer if griddling). Sprinkle with coriander, if you like, then serve with rice or slide into pitta breads.