Preparation Preheat oven to 400°F. Spread out parsnips in single layer on rimmed baking sheet. Roast parsnips until brown, stirring occasionally, about 30 minutes. Melt butter in heavy large saucepan over medium heat. Add onion and sauté until beginning to brown, about 5 minutes. Add parsnips and sauté 5 minutes. Add stock and boil until parsnips are tender, about 5 minutes. Remove from heat. Working in batches, puree soup in blender. Return to saucepan. Stir in allspice. Season with salt and pepper. (Can be made 2 days ahead. Cool, then cover and chill.) Bring soup to simmer. Ladle into bowls. Top with bacon and dollop of sour cream, if desired, and serve.
Preparation Preheat oven to 400°F. Spread out parsnips in single layer on rimmed baking sheet. Roast parsnips until brown, stirring occasionally, about 30 minutes. Melt butter in heavy large saucepan over medium heat. Add onion and sauté until beginning to brown, about 5 minutes. Add parsnips and sauté 5 minutes. Add stock and boil until parsnips are tender, about 5 minutes. Remove from heat. Working in batches, puree soup in blender. Return to saucepan. Stir in allspice. Season with salt and pepper. (Can be made 2 days ahead. Cool, then cover and chill.) Bring soup to simmer. Ladle into bowls. Top with bacon and dollop of sour cream, if desired, and serve.