Mix the flour, yeast and sugar in a large bowl. Add the water gradually and mix. Add salt and mix until the dough is formed. Fold it 2-3 times, cover and let it rise in a cool place for 20 hours.
Preheat the oven to 430 F (220 C) and put in a round baking pot or a deep baking pan. Transfer the dough to a lightly flour-dusted surface, roll it out and top with the olives. Fold the dough inward and shape it into a loaf (round or oval). Transfer back to a bowl, cover and let it rise for 40 minutes.
Create a cut on the top surface of the dough with a sharp knife. Remove the pot from the oven, place the dough inside (careful, the pan is super hot), cover with a lid or tin foil and bake for about 30 minutes. Uncover the pot and continue baking until you get a brown/golden crust.
Remove from the oven and place on a wire rack. Wait at least 40 minutes before slicing.