Either boil 2 large potatoes in their skin, or peel, dice and boil until tender.
Mash and leave to cool down.
Add the yeast to the warm water, give it a stir to dissolve, and leave to rest for 1 minute
In a large bowl, sift the flour, add the cooled mashed potatoes, salt, oil and yeast mixture, and knead well for about 5 minutes to get a smooth and elastic dough that does not stick to the hands.
Cover the bowl with clingfilm, and leave to prove in a warm place for about 2 hours or until it doubles its volume.
Knead the dough gently again, shape it in a ball, then flatten it up slightly.
Transfer the bread to a floured baking tray and leave to prove again until double in size.
Preheat the oven to 220 degrees Celsius (430 Fahrenheit).
Add hot water to the dripping pan set at the bottom of the oven, and bake for 20-25 minutes until golden brown and when given a sharp knock on the bottom of the bread, it sounds hollow.
Leave to cook down on a rack before slicing.