1. Rub pork stomach with salt and corn starch, then wash clean, remove yellow bits with small knife.
2. Blanch chicken feet and pork neck bone, drain and rinse, set aside.
3. Peel, slice and smash ginger; smash white pepper corns. Prepare a pot of water, add chicken feet, pork neck bone, ginger and half of the smashed pepper corns, bring to a boil.
4. Stuff the remaining white pepper corn into pork stomach, together with gingko seeds, lilies of the field, pearl barley and lotus seeds until the stomach is 80% full, then seal with a bamboo skewer.
5. Blanch the pork stomach in boiling water, when the stomach expands like a ballon, transfer it to the pot for soup. Bring to a boil in high heat, then simmer in low heat for 1.5 hrs.
6. Soak pickled leaf mustard in water for a while before slicing, tip into the soup and boil for half an hour with lid on.
7. Transfer the pork stomach to a large serving bowl, remove the bamboo skewer, scoop out the ingredients, pour the soup into the bowl, cut the pork stomach up with scissors, serve.