Wash the potatoes and boil them, skin on, with 2 teaspoons of salt until they are soft. Drain them and keep the water aside. When cool, peel the potatoes and mash them.
Mix the fresh yeast with a teaspoon of brown sugar. Add two teaspoons of flour and mix again. Sprinkle some flour on top too. Keep aside until bubles. If you use dry yeast, jump to the next step.
Measure 120ml from the water in which you’ve boiled the potatoes. Dilute the activated yeast with this water. If you chose to use dry yeast, simple stir the yeast and brown sugar with this potato boiling water.
Mix the potatoes with the flour and the two remaining teaspoons of salt. Add the liquid with yeast and the oil and knead vigorously (preferably in the bread maker or food processor), processing it for about 10 minutes. The dough becomes supplier and slightly sticky. Put the dough in a bowl and leave it to rise for 35 minutes at room temperature, covered with cling film.
Place the risen dough on the worktop (previously sprinkled with flour) and cut it in two equal parts. Flatten each piece in an oval shape and roll one side toward the interior up to the midpoint. Dust the opposite side with some flour. Powder a kitchen towel with flour and place the breads on it, with the joint (the unrolled side) facedown, shaping them in a relatively round form. Cover them with another kitchen towel and leave them to rise at room temperature for 35 minutes.
Heat the oven at 230 degrees Celsius and place a small pan with hot water inside, for steam. If your oven has a steam baking function, you will not need to put the small pan inside it. Lay the breads on a tray covered with baking paper, in a position opposite from the one they were left to rise in (with the joint face-up) and bake them in the oven at a height situated in the inferior half. After 15 minutes, remove the pan with hot water (be careful with it!) and reduce the heat to 190 degrees Celsius. Bake the breads for 30 minutes more.
Take them out and place it on a baking wire rack, waiting for it to cool completely before cutting it.
Use the step by step instructions above (with pictures) for a more accurate result.