Soak cashews*: Place half the cashews in water for 3–4 hours or overnight.
Cook beetroot: Boil until tender (20–60 minutes depending on size). Cool, peel, and dice.Skip this step if using pre-cooked beetroot.
Prep veggies: Clean leek thoroughly, chop (reserve a few slices for garnish). Quarter cabbage, remove core, and chop finely. Peel and chop onions.
Sauté: In a large pot, heat oil. Sauté onions until translucent. Add leek and cabbage, cook 5 minutes.
Simmer: Add broth and marjoram. Simmer covered until cabbage is tender (15–30 minutes).
Toast cashews: Roast remaining cashews in a dry pan until golden.
Blend cashew cream: Drain soaked cashews and blend with 200 ml water (about 1 scant cup) until smooth. Stir into soup. Purée soup until creamy. Season with salt.
Serve: Ladle soup into bowls. Top with beet cubes, roasted cashews, and reserved leek slices.
Notes
*We’re using half of the cashews to make a creamy base. If you’d rather skip this step, just swap in 300 ml (about 1 ¼ cups / 10 fl oz) of ready-made vegan cooking cream. In that case, no soaking needed — you’ll only need 100 g (about ¾ cup / 3.5 oz) cashews for toasting as the crunchy topping.