Wash, clean and, if necessary, chop the vegetables. Bring the water to a boil.
Heat the olive oil in another large saucepan and sweat the vegetables in it. Add the ginger slices, ground mustard seeds, pepper, bay leaves, a pinch of salt, lemon wedge, thyme, juniper berries and fenugreek seeds.
Deglaze with the hot water, simmer the soup for 3-5 hours on a small fire and then strain everything.
Serve the soup sprinkled with chopped parsley.
In traditional Chinese medicine, this soup is particularly recommended for women in childbed.