Celery Root and Wild Rice Chowder

1/2 cup wild rice1 celery root2 large leeks, white parts only2 Tbs unsalted butter1 celery rib, diced1 cup thinly sliced potatoes1/4 cup parsley1 bay leaf1 large thyme sprigsalt and pepper2 cups vegetable stock, chicken stock, or water2 cups half and half or milk Cover the wild rice with 5 cups of water in a small sauce pan.  Bring to a boil, then lower the hat.  Cover and simmer for about 45 minutes, or until tender.Thickly cut away the celery root skins, then quarter and chop the root into bite-sized pieces.  You should have about 3 cups.  Chop and wash the leeks.Melt the butter in a soup pot.  Add the vegetables, parsley, bay leaf, thyme, and 1 1/2 tsp salt.  Cook over medium high heat for about 5 minutes, then add the stock.  Bring to a boil, reduce the heat to low, and simmer for 20 minutes.  Add the half and half and simmer until the vegetables are tender.  Taste for salt and season with pepper. If you'd like the soup to be creamier, puree a cup of the vegetables and return them to the pot.  If the soup is too thick, thin with some of the rice water or additional stock.Divide the soup among 4 or 6 bowls and then add a mound of the wild rice to each.  Garnish each bowl with parsley and serve.