Combine first 7 ingredients in a shallow roasting pan. Bake at 450° for 30 minutes.
Place vegetable mixture in a Dutch oven over medium heat. Add flour, ginger, and sage; cook 3 minutes. Add Vegetable Stock, and bring to a boil. Cover, reduce heat, and simmer 30 minutes. Stir in salt and pepper. Sprinkle each serving with 1 1/2 teaspoons parsley and top with 1 teaspoon crème fraîche.