Combine marinade ingredients in a bowl. Add lamb and marinate for 2-3 hours. Remove marinated lamb and drain in a colander. Put in a pot with just enough water to cover, bring to the boil then allow to simmer for 1 hour.
Remove lamb pieces from the stock and deep-fry in hot oil for about 10 minutes. Leave 2 tablespoons oil in the pan and simmer the remaining marinade sauce ingredients for 5-10 minutes.
Put fried lamb pieces on a piece of foil. Add simmered sauce ingredients, then wrap up and grill in a preheated grill at 200°C for 15-20 minutes. Remove and serve immediately.