Crumble the yeast and dissolve in 400 ml of lukewarm water while stirring. Mix flour and salt in a large bowl. Add yeast water and olive oil. Mix everything with the dough hooks of the mixer on a low setting, then knead on the highest setting and finally quickly knead with your hands to a smooth dough.
Cover the dough with a clean tea towel and leave to rise in a warm place (e.g. on or on the radiator or in a 50 °C oven) for about 2 hours until it has doubled in volume.
Grease the box mould and dust with flour. Place the yeast dough on a lightly floured work surface and knead briefly with your hands.