Pour the tomato puree, sauce, tomato paste, and chicken broth into a large pot. Stir together until fully combined and cook over medium heat.
In a measuring cup or small bowl whisk together the milk and gluten-free flour until fully combined. Pour the milk mixture into the tomato mixture and stir together until fully combined.
Add the salt, garlic powder, onion powder, and brown sugar to the soup and stir until combined. Cook over medium heat for 10-15 minutes, or until the soup thickens.
Serve warm and enjoy!
Store leftovers in an airtight container in the refrigerator.
Reheat the soup in the microwave or on the stovetop.
Video
Notes
The soup can be frozen. Allow the soup to completely cool at room temperature or in the refrigerator. Place in a freezer-safe container, and store it in the freezer for up to six months.
Thaw the soup overnight in the refrigerator and then reheat. When reheating, make sure to stir the soup to combine any milk that may have separated in the freezing.
If you are batch cooking, you can make the soup and skip the milk mixture. You can add the milk mixture when you are reheating the soup.