Uncover the bread bowl. The dough inside will be bubbly and very slightly risen. Transfer it to the bowl of a stand mixer and add the rest of the flour, 300ml warm water, 3 tbsp olive oil and 3 tsp salt. Mix everything with a wooden spoon just to get it started and then attach the dough hook to your machine and mix on medium speed. The dough will seem quite wet but do not add any more flour. Keep mixing until it comes together as a silky textured ball of dough (this could take 10 minutes or more). Put into a large, clean bowl and leave for about 1 hour until almost doubled in size.