Currywurst is a typical German take-away dish, a hot pork sausage cut into slices and seasoned with ketchup and generous amounts of curry powder, or a ready-made ketchup-based sauce seasoned with curry and other spices. Usually served with french fries or bread rolls(called "Brötchen"), it is particularly popular in the metropolitan areas of the Ruhr Area, Berlin, and Hamburg. Considerable variation both in the type of sausage used and the ingredients of the sauce occurs between these areas, and there are disputes over where currywurst was originally invented and which version is to be considered "correct".