Soak 100 g cashews in water for 3-4 hours or overnight.
Cook beetroot in water until the beet is soft (it’s done when you ca easily poke it with a knife through the middle). If you have just one (large) beetroot, it may take up to an hour until it’s cooked; Two or three smaller ones usually take between 20 and 30 minutes. Leave to cool when done.
Cut off the hairy end of the leek (the root part) and discard also the dark green ends. Slice the leek lengthwise, fan it open and clean it under running water. Make sure esp. to get rid of the dirt between the individual layers. Chop the leek and put some pieces aside to decorate the soup.
Wash the cabbage, cut it into quarters, and discard the core of each quarter. Chop the quarters finely.
Peel the onions, chop them and saute them in rapeseed oil until they are translucent. Add leek and cabbage to the onion, saute for 5 minutes, then add the vegetable broth and the marjoram. Cook with a lid on until the vegetables are soft (about 15-30 minutes).
Rinse the soaked cashews and blend them with 200 ml of water until you get a smooth cream. Add the cream to the soup and puree it. Taste test and add salt if needed.
Roast 100 g cashews in a pan.
Peel cooked beet and cut it into small cubes.
Serve the soup hot, topped with beet cubes and roasted cashews.