By Lucy Madden
This is a simple version of the famous Portuguese cabbage and potato soup that is traditionally served with a corn bread called broa. Kale can be substituted for the cabbage. Cavalo nero, unknown to me twenty years ago, would be excellent.
Cook the potato slices in the salted water until soft. Remove and purée them with the olive oil, then return to the cooking liquid. Bring to the boil, add the cabbage and cook for no more than 8 minutes. Serve with a sprinkling of cheese.