Mix all the ingredients for the marinade in a large shallow dish.
Cut the beef into thin strips about 8 mm/⅓ inch wide and 15 cm/6 inches long. Thread the strips onto skewers, place in the marinade and turn to coat the meat, then leave in the fridge for 1 hour.
Place the skewers under a hot grill and cook for about 2 minutes on each side, making sure