To make the sourdough loaves add the water, 500g strong white bread flour and salt to the bowl.
Pour in 300g of the starter, attach the dough hook and knead well on speed 1 for 10/15 minutes, until you have a strong, smooth and elastic dough.
Remove the bowl and cover with a damp cloth and leave to rise for 3 to 4 hours.
Flour a work surface and remove the dough from the bowl. Divide the dough into two, knock the air out and shape into buns. Lightly oil two bowls and place the dough into the bowls, cover and leave for three hours.
Heat the oven to 250°C and line a baking tray with baking paper.
Remove the dough from the bowls and place onto a baking tray, give a good dusting of flour and score a cross in the top of each loaf.
Boil the kettle, pour some of the water into a shallow baking tray and place in the bottom of the oven (this creates steam to help make a crust).
Bake the loaves in the oven for 35 minutes or until the bottom sounds hollow when tapped. Leave to cool on a wire rack for about an hour.