For the potato bread, peel the potato, cut into small cubes and boil in salted water for 10 minutes. Save 390ml of water for the dough.
Work all ingredients into a smooth dough and then let rise for a good 1 hour. Knead and form a loaf. Roll in flour and let rise again.
Bake in a large Roman pot or similar at 230 degrees O/U heat with a lid for about 50 minutes, then bake again without a lid for about 5 minutes to crisp it up.