NOTE - Unless you use the Bertinet method you will find this dough very wet and sticky at first. Try not to use extra flour as you will change the recipe
Method
The Poolish
Mix the yeast and water together and then add the flours. Cover with a plastic bag and leave overnight in the fridge (or for 6 hours at room temperature). The slower the better.
The Bread Mixture
Turn the oven on to gas 8 (250 degrees) and place either a baking stone or an upturned baking tray on the shelf.
Leave the ferment in the bowl and add the rest of the ingredients, except the salt.
Mix everything together and start working the dough. After about 10 mins add the salt and work into the dough.
Lightly flour the work surface and the bowl. Form the dough into a ball and put it back into the bowl to rest for 1 1/2 hours.
Turn it out onto the work surface and cut it into 200g pieces. I let it rest for 15 mins and then roll the pieces into baguette shapes and put them onto floured tea towels, with folds in between, and let them rise for another 1 1/2 hours.
Use a water spray and squirt about 10 times into the oven. Now transfer the loaves onto the shelf using a baking peel or upturned baking tray, lightly sprinkled with cornmeal, or similar, to help them slide. have another quick squirt and shut the door.
Bake for 15 mins the take them out and put them on a cooling rack.
You could also make loaves etc
About 850g to 900g of dough makes a large loaf.