Peel the onions and ginger. Chop the onions finely and grate the ginger "fine" with a fine blade. Fry in 1 tsp oil. Peel the sweet potatoes (except for one for the chips) with a professional peeler and then coarsely chop. Add to the onions and fry briefly. Deglaze with the vegetable stock and cook until soft, about 15-20 minutes.
Meanwhile, peel the small sweet potato with a professional peeler and also peel/slice finely for the chips. Heat 1 tbsp oil in a separate pan and brown the slices nicely. Place on a plate and lightly salt.
Now puree the soft sweet potato soup with a blender. Add the coconut milk and bring to the boil. Season with salt, pepper and cumin. Add more or less hot curry to the soup to taste.
Serve in a bowl and top with the chips. Finally, grate fresh coconut over the top with a coarse blade.