Heat a nonstick saucepan over medium heat; fry Szechuan peppercorns, cinnamon stick and mandarin peel for a minute until fragrant. Add wine, thick soy sauce, ginger and spring onion. Lastly, add sesame oil. Stir and simmer over a gentle low heat for 1-2 minutes.
Place lamb cutlets in a bowl, pour the prepared hot marinade over. Stir the marinade to coat the lamb pieces. Leave aside to marinate for at least 30 minutes.
Sauce: Heat oil, ginger and garlic over medium low heat. Stir until fragrant for 1-2 minutes. Add light soy sauce, oyster sauce, sugar, black vinegar and water. Bring to a low simmering boil to dissolve the sugar.
Remove marinated lamb cutlets from the marinade, discarding the marinade. Heat a large frying pan over medium low heat and place the lamb cutlets on the bottom. Cook lamb pieces for 2 minutes on each side or until browned.
Pour the prepared ginger sauce over the lamb and simmer for a while until meat is cooked to the right texture. Serve at once.