In a large pot add Chicken Broth, pepper, garlic salt, onion and broccoli. Let come up to an easy boil. Trun heat down to a medium. In the mean time place the milk in a smaller pot on medium heat (you do not want the milk to burn). When the milk is heated, add the cream cheese. With a wisk stir the milk and cream cheese until completely smooth. Add the butter, stir. Add shredded cheeses 4 ounces at a time. Stiring until smooth. Add salt and pepper to taste. Once the cheese mixture is completely incorporated add it to the larger pot with the broccoli. Stir. Place the 2 tablespoons of cornstarch in a cup with a bit of water (just enough so it is not pasty) stir together. Pour in the soup while stiring. Let the soup cook for 15 minutes after the cornstarch has been added. This is just to thicken the soup. If you want it thicker add more cornstarch by repeating the previous step. Or if you don't want to use it then you don't have too. Serve and enjoy!