1. Combine carrots and 2 cups water in a pot. Bring to a boil. Cover, reduce heat and simmer 35 minutes or until very tender. Drain and set carrots aside.
2. Combine parsnips and remaining 2 cups of water in pot. Bring to a boil, reduce heat, cover, and simmer 20 minutes or until very tender. Drain and set aside.
3. In food processor, process carrots, 1⁄2 cup soy or rice milk, 2 teaspoons margarine, and vanilla. When smooth, pour into pot. Cook over medium-low heat for 5 minutes, until fully heated, stirring occasionally. Set aside.
4. Clean food processor bowl. Process parsnip, 1⁄2 cup soy or rice milk, remaining 2 teaspoons margarine, sugar, and salt until smooth. Pour into a pot and heat through for 5 minutes.
5. Spoon carrot mixture into half of a pretty serving dish. Place parsnip mixture in other half. Pull a fork through mixtures to create a marbled pattern.