Cauliflower Soup

INGREDIENTS

• 1 stick Butter, Divided
• 1/2 whole Onion, Finely Diced
• 1 whole Carrot Finely Diced
• 1 stalk Celery, Finely Diced
• 1 whole (to 2 Whole) Cauliflower Heads (roughly Chopped)
• 2 Tablespoons Fresh Or Dried Parsley, Chopped
• 2 quarts Low-sodium Chicken Broth Or Stock
• 6 Tablespoons All-purpose Flour
• 2 cups Whole Milk
• 1 cup Half-and-half
• 2 teaspoons To 4 Teaspoons Salt, To Taste
• 1 cup (heaping) Sour Cream, Room Temperature