Soak mushrooms in cold water. Defrost lotus root at room temperature. Peel onions and cut into fine strips. Clean, wash and roughly cut Pak choi into strips
Pour the mushrooms into a sieve, drain and cut into strips. Heat oil in a pan and fry lotus root slices in it for about 6 minutes. After about 2 minutes add onions and Pak choi. Add the beans, bring to the boil, season to taste with Hoi Sin sauce
Waiting time approx. 1 hour