(flatbread with cheese filling) Melt the yeast in lukewarm water and a third of the oil. Put the flour in a suitable bowl and form a hollow in the middle. Pour the dissolved yeast and cover with flour. Cover the baking bowl with a kitchen towel and let the dough rise for half an hour.
Now knead the dough with half of the remaining olive oil until it is nice and smooth. Leave to rise for another half hour in a warm place, protected from drafts.
Then briefly knead the dough again and divide it in half.
Preheat the stove to the highest setting.
Roll out the dough thinly on a floured surface and divide into two halves. Brush a baking tray with oil and spread with one half of the dough. Dice the cheese and spread it on top. Cover with the second sheet of dough. Smooth out and press together at the edges. Brush with the remaining olive oil, season with salt and prick with a fork to prevent the focaccia from bursting during baking.
Put the focaccia in the oven and bake until golden brown (about 20 minutes).
Serve while still warm.