Finely slice the onion, ginger and garlic. Cut the mushrooms into chunks and the beans into 3-4 cm pieces.
Heat the oil in a wok over medium-high heat. When it’s smoking hot, add the onion and stir-fry for 3 minutes until brown then add the garlic and cook for 30 seconds.
Add the mushroom, stir fry for a minute then add the rice wine and soy sauce. Add the beans, turn down the heat and put a lid on.
Saute for 3 minutes, until the beans are tender.
Stir in the sesame oil.
Serve with some sesame seeds sprinkled on top.