Mix the lamb with sugar, sherry, soy sauce and the five-spice mixture and marinate it for about 1 hour. Heat the oil in a frying pan or wok. Add the lamb and roast it until the pores have closed and it has turned a golden brown color on all sides. Add onion, ginger, garlic and ground pepper and roast again for about 2 minutes.
Add the remaining marinade and clear soup, bring it to a boil and then simmer for about 1, 5 hours.
Add the potatoes and make everything together for about half an hour until the potatoes are soft **.
Tip: Always use aromatic spices to refine your dishes!