Dissolve the yeast in the warm water.
Then add this with the flour, 250g cold water (save the 30g extra water for later), sourdough starter, malt flour and olive oil to the mixer bowl.
Mix on first or the lowest speed for 3-4 minutes until almost combined, then increase the speed to 2-3 and mix for about 10 minutes until the dough is quite smooth elastic (stop the machine and scrape the dough down from the top of the dough hook if it twists up).
Next add the salt, and gradually the water in 2-3 slurps, and mix until the dough is very smooth and elastic (almost like chewing gum).
Remove the dough from the mixer’s bowl and place in a lightly oiled container to rise: with the Ankarsrum remove the dough hook and scraper first, then it’s super easy to lift the dough and bowl out to do this.
Cover and leave to rise for 90 minutes.
Give the dough a stretch and fold on an oiled surface (I use an oiled tray, with a damp cloth folded and placed under it on the worksurface to stop it wobbling) then return the dough to the container leave the dough a further 70-90 minutes until almost doubled in volume.
Get a baking tray and place a sheet of non-stick paper on it that covers the surface edge-to-edge.
Lightly oil the paper, and a few dabs of oil under the paper will stop it from moving.
Stretch and fold the dough once more, as before, then place it in the centre of the paper.
Cover and leave to rise for 20-60 minutes, then oil the top of the dough and dimple it outward to almost reach the edges of the trays.
Heat the oven to 220C fan.
Leave the dough to rise for 30 minutes more, then sprinkle with sea salt flakes and bake for about 30 minutes until a rich brown colour on top and well risen.
Remove from the oven, drizzle with a little more olive oil while hot then leave to cool.
