In medium saucepan, stir-fry sausage, onion, and celery in oil. Add garlic; cook 1 minute. Add water, cauliflower, tomato, carrot, and seasonings; bring to a boil. Reduce heat and cover; simmer 15 minutes. Stir in wild rice and 2 cups milk. In small bowl, whisk flour into ½ cup milk; whisk into soup, stirring constantly. Bring to boil; cook until thickened, stirring constantly. Remove bay leaf.