Even though the oven will reach the temperature after 20 or 30 minutes depending on your oven's capacity, it is really necessary to wait an hour as the baking stone will take longer to reach its maximum temperature. This initial contact with a very hot stone gives the bread 'bounce' or rise. Unless you are using the oven for something else, you can switch the oven off a good 5 minutes before the time is up as the stone with retain a lot of heat.
500 Strong white bread flour
10g Sea salt
½ tsp yeast
350g luke warm water
Mix all ingredients in a stand mixer for 4 minutes on low speed and then 6-7 minutes on a high speed, until the dough comes off the sides of the mixing bowl. Cover the bowl with cling film and allow to rise in a warm place for 1- 1 ½ hours until the dough has doubled in size.
Tip onto a lightly floured surface and gently stretch into a rectangle, fold the top third to the middle and then the lower third, now fold in half and press the seams gently together to seal them.
If the dough is very loose, allow to rest for 15 minutes and repeat. Shape into a ball taking care to keep the surface structure intact as this will hold it together.
Now pick up with a dough cutter and place the ball seam side up in a well dusted Banneton. I use white rice flour here. Cover lightly and allow to rise until it fills the Banneton - this will take about 60 - 90 minutes.
Prepare the oven with a steam tray and preheat with a baking stone to 240 or at hot as you oven will go. Just before placing in the oven, tip a half a cup of water in the steam tray and close etc oven so the steam does not escape.
Tip out to the banneton onto a peel and score with a lamé. Place on the hot baking stone and bake for 25 minutes (10 minutes on 240 degrees and 15 on 200).