In a large pot or Dutch oven, heat the oil then add in the carrots, celery, turnips, sweet potato, garlic, scallions, and ginger. Saute for about 5-10 minutes then add flour and mix well. Next, add the soy sauce, broth and water and mix well. Bring to a boil, reduce heat then let simmer for 45 minutes or until all the vegetables have softened. In a separate saucepan, heat the cream and milk. Use your immersion blender* to blend all the ingredients together. Season with salt and pepper and garnish with chopped scallions. Makes 8 cups.