Heat the wok until very hot, add the sesame seeds and stir-fry over high heat until they are golden. Remove from the wok and set aside. Reheat the wok, add the oils and swirl to coat the side. Add the spring onion, salt,pepper, honey, and beans, and stir-fry for 4 minutes. Add the mushrooms and ginger, and cook for 4 minutes. Pour in the mirin, tamari sauce and sugar, cover and cook for 2 minutes, or until the beans are tender. Sprinkle with the toasted sesame seeds.