Combine ½ cup flour with the yeast and 1 cup water in the bowl of an electric mixer. Stir well with the paddle attachment, then set aside for 15 minutes until very foamy. Add half the remaining flour and ½ cup water, then beat with the paddle attachment on medium speed for 10 minutes, until thickened. Cover with cling film, then set aside for 1½ hours, until the batter has risen and fallen.
Add the remaining flour and salt to the batter, then mix with the dough hook on medium speed for 5 minutes, until smooth. Add the oil, then mix for 3 more minutes. Cover with cling film and set aside for 40 minutes, until doubled in size.
