Beetroot Soup with Purple Potato Chips
Peel and cube the beetroot. Peel and dice the red onion. Melt the butter in a saucepan. Fry the beetroot and onions. Add the sugar and vinegar. Add the broth, then season with salt, pepper and cumin. Cook over medium heat for about 25 minutes, or until the beetroot is tender.
Purée the contents of the pot in an electric blender, season with salt, pepper and some vinegar to taste. Serve in soup plates, topped off with 1 tablespoon of sour cream, and the potato chips.