Knead all of the ingredients together at low speed, except the yeast, for 4 minutes, then add the yeast and knead at high speed for a further 6 minutes, until the dough is even. Divide into 1200 g portions. Rest uncovered at room temperature for 20-30 minutes. Lay out the dough on greased 60×40 cm baking trays. Top as desired, brush with oil and salt the surface. Leave to rise in a proofing cabinet at 30°C with 75% RH for 60-90 minutes. Bake at 210°C for 25 minutes, with initial steam.