Peel and dice the potatoes and cook in vegetable stock for 8 minutes. Now add the red lentils and cook for another 8 minutes. Dice the beetroot and add to the still hot vegetable stock, leave to stand for 10 minutes.
Pour off the broth, add the vegetable drink and finely puree the vegetables with a blender. Season with salt, pepper and nutmeg.
Cut the onions into half rings and fry them brown in a little oil, caramelize with a little sugar and salt and serve on the puree.