Place ribs in a large stock pot and cover with water. Bring to a boil and cook for 15 minutes.
In a mixing bowl, combine together the tomato soup, onion, garlic, brown sugar, Worcestershire sauce and soy sauce. Remove ribs from water and transfer to a slow cooker. Pour sauce over ribs.
Cover and cook on Low for 6 to 8 hours, or until ribs are tender.
If sauce is too thin when cooking time is done, drain sauce from ribs and pour into a saucepan. Combine the cornflour with the cold water then stir into sauce and bring sauce to boil. Cook until the sauce has reached your desired thickness.
For Gluten Free options, ensure to use the wheat free soy sauce and cornflour.