Cut the bell pepper and the onion into small pieces. Cut the sausages into slices.
In a large saucepan, heat the curry and tomato ketchup, tomato puree, tomato paste and water and add the bell peppers. Heat the oil in a pan and fry the onion in it. Now gradually fry the sausage slices and then add everything to the saucepan, season with the spices and bring to the boil. The currywurst pot should simmer for about 90 minutes.