Heat butter in a heavy soup pot over medium heat. Add the carrots, leeks, and celery and cook about 5 minutes, stirring occasionally Reduce the heat to low and add the flour. Cook this for about 3 minutes, stirring constantly. Add the stock to the flour and vegitable mixture, slowly, whisking to avoid lumps. Bring the soup to a simmer. then add the wild rice and salt. Simmer for 45 minutes until the rice is tender, but still a little chewy. Add the heated cream, sherry, and chives. Season with salt, if necessary. Serve in bowls garnished with parsley.