Preparation Melt butter in heavy large pot over medium heat. Add next 5 ingredients and sauté until vegetables are tender, about 5 minutes. Stir in broth and parsnips; bring to boil. Reduce heat to medium-low and simmer until parsnips are tender, about 20 minutes. Cool slightly. Working in batches, puree soup in blender until smooth. Strain into another large pot; discard solids in strainer. Whisk in half and half. (Can be made 1 day ahead. Cover; chill.) Simmer soup over medium heat until heated through, about 10 minutes. Season soup with salt and pepper.