Miracle Mushroom is another side quest found within Bailu Village, it requires you to find a certain Mushroom.
In order to trigger the quest itself you need to speak to Kong Mei in the market area of Bailu, Kong is a merchant and often resides within her store.
Upon speaking to Kong Mei she will ask for a specific Mushroom, a Miracle Mushroom to be precise and these only grow in certain areas.
Thus without any real knowledge this can be a tricky one to find. However, the Mushroom is actually found near the Verdant Bridge near a sort of out of the way fishing spot.
Related Guides / Links: