Peel the beetroot, grate 2/3, put the remaining beetroot aside. Peel ginger and chop finely. Clean and wash lemon grass. Lightly tap 1 stalk of lemongrass with the back of a knife and cut it into coarse pieces, remove the end of the remaining lemongrass stalk, peel the leaves and set aside for garnishing
Heat ghee in a pot. Roast cumin in it for about 1 minute while stirring until it smells good. Add grated beetroot, ginger, coriander, cloves, cinnamon and cardamom and braise for 2-3 minutes. Deglaze with broth. Add chopped lemongrass stalk and simmer covered for about 30 minutes. Pour through a sieve
Finely dice the remaining beetroot. Put the soup back into the pot, add diced beetroot and bring to the boil. Cover and simmer for about 10 minutes. Season to taste with salt and pepper. Arrange soup in bowls, garnish with lemon grass leaves and coriander