Core the cabbage and cut into pieces (do not shred).
Heat the oil in a large frying pan and add the onion. Cook 7-10 mintues til softened and lightly browned. Add the cabbage and potatoes and season with salt and pepper. Cover and cook on medium-low heat for 25-30 minutes, stirring occasionally until the potatoes are tender.
Add the franks after 15 minutes of cooking time. Add a little boiling water to prevent burning, if necessary.
Heat the caraway seeds in a dry frying pan till lightly toasted and sprinkle over the cabbage mixture before serving.