Pour hot water over the wood ear mushrooms and leave to rehydrate for 10-15 minutes.
Wash the Chinese cabbage leaves and blanch in boiling, salted water. Refresh in cold water and lay on a work surface covered with a kitchen towel. Wash the chives. Squeeze out the mushrooms and chop finely.
Mix with the rice and chilli sauce and spoon onto the Chinese cabbage leaves. Gather up the edges of the leaves to form purses and tie each purse with two chives. Snip the rest of the chives. Put the vegetable stock into a wok and bring to the boil.
Season with saffron threads, rice wine and soy sauce. Reduce the heat, add the rice purses and infuse in the soup for a few minutes. Stir in the sesame oil shortly before serving.