In a large pot melt the butter over medium heat. Add the onions and sauté for about 4 minutes, until tender. Add the rutabagas, carrots and parsnips and stir, then pour in the broth, raise the heat to high and bring to a simmer. Lower the heat to medium and simmer, covered, for about 25 minutes until the vegetables are very tender.
Add the sage leaves and honey and use an immersion blender to puree the vegetables right in the pot, or carefully transfer the vegetables and some of the liquid in batches to a food processor or blender and puree with the sage leaves and honey until smooth. Return the soup to the pot, add the cream and heat over medium high heat for another minute until the whole thing is heated through.
Serve hot in bowls with the parsley and goat cheese sprinkled on top.