Boil the potato for 15 minutes. Dissolve the yeast in the water together with the sugar and let it rest for 5 minutes. In a bowl, pour the flour and salt and mix, add the boiled and mashed potato, the oil and the yeast dissolved in warm water. Knead for 15-20 minutes, if necessary help yourself with the other flour, it must be a well-strung dough. Make a loaf, cover with a cotton cloth and let it rise in the oven turned off for 2 hours it must double in volume.
While the dough is rising, let’s prepare the filling;
Clean the spinach and cut it into slices, cut the black olives in half;
Take a pan, pour in the oil, add the onions and brown them lightly;
Then add the olives, season with salt and pepper and cook for 5 minutes, stirring occasionally;
Now let’s take the dough again, first grease the pan well (I use the 28 cm diameter one), then divide the dough in two, roll it out and place it on the base of the pan, letting a little dough stick out;
Fill with the onion and olive mixture, place the other sheet of pastry on top and close;
Then we close with the pastry that we let come out, with the fork we make a small design all around, grease with more oil, prick and bake at 200 degrees for about 1 hour… check the cooking, it depends on the ovens;
