See recipe for Chicken Stock. Cut off and reserve the top of the pumpkin. Use a large spoon or melon baller to scoop out and discard all of the seeds and strings. Scrape out the pumpkin flesh without breaking through the shell. You should have about 6 cups of pumpkin pieces. Set aside the hollow pumpkin and lid. In a large casserole, heat 2 tablespoons of butter over medium heat. Add the onion and saute, stirring often, until softened and very lightly golden, about 6 minutes. Add the wine and simmer for 1 minute longer. Add the turnips, carrot, reserved pumpkin flesh, and enough Chicken Stock to cover solids. Season lightly with salt and pepper. Cover and bring to a boil. Meanwhile, cut the bread slices into thin wedges about 1 cm long. In a large skillet, heat 3 tablespoons of butter over medium heat. Add half of the bread pieces and toss constantly in butter until lightly golden, about 5 minutes. Add these croutons to the soup. Saute the remaining uncooked croutons in the remaining butter, set aside for garnish. Boil soup gently, covered, for 1 hour. Puree mixture in a processor or blender until smooth. Return the pureed soup to a clean saucepan, stir in the cream, and bring to a simmer. Thin, if necessary, with additional stock. Adjust seasoning with salt and pepper. Serve soup in pumpkin, passing remaining croutons separately.