"Plommek soup is tradtionally served with a spoonful of sour cream on top; this is carefully swirled out with a spoon to amke a spiral shape, representative of the galaxy. The outline of the galaxy is then emphasized with very finely chopped parsley. for less festive occasions, it may be served with a small spoonful of butter (or maragarine) in the centre.
In the pot, melt the butter and when it is foamy, add the onion and fry until golden. Add everything else to the pot except the last cup of water and the sour cream and parsley garnishes. simmer, covered, for about 15 to 20 minutes, or until the potatoes and carrots are tender. Run it all through the blender, about 1 to 1 1/2 cups at a time. When it is all pureed, rinse the cooking pot with the cup of water and add that to the 'empty' blender. Run the blender for a few seconds and then slosh the water about to get as much of the vegetable puree as possible off the sides of the blender. Add this liquid to the soup. Pour the soup back into the cleaned out pot and reheat it before serving (use very gentle heat). Ladle into bowls. Garnish with sour cream and parsley as described above.