Once boiling, reduce the heat to medium-low and simmer the soup for 15 minutes. Stir in the cheese and the half & half and then gently heat the mixture until the cheese has completely melted. Serve ho. Aug 1, 2016. How to Make 20 Minute Broccoli Cheese Soup (Video). and flavor and naturally low in fat and calories it's the perfect lunch, snack or starter! Keep the soup warm over…