Add the water to the bowl and then add the yeast. Wait for five minutes to let the yeast dissolve and then squish the biga/water mixture together with your hands to make a milky paste.
Add the fresh flour and the salt. Stir it all together well. Add the potato and the rosemary and give it another stir/knead to make sure it's all incorporated evenly and then add the beets and give the dough another gentle stir/knead so you don't squash the beets to death.
Cover the dough and leave it for 30 minutes.
Lovely open crumb, beautiful to look and and amazing to eat!Image note: Lovely open crumb, beautiful to look and and amazing to eat!
Stretch and fold the dough and then let it rest for 30 minutes.
Repeat this four times. If you are not sure what it means to "stretch and fold" you can watch a little video. https://www.youtube.com/watch?v=2zM50RHnWvE
Scrape the dough out onto a lightly floured surface and divide it into four equal pieces.
Cover and let rest for 20 minutes.
Shape the dough into a ciabatta shape.
Cover and let rest for 30 minutes.
Preheat the oven to 230 degrees C and pop the dough in. Bake for 20 minutes and then remove and let cool completely on a cooling rack.