Roughly mix flour, water and leaven by hand in a plastic tub, holding back the salt until the leaven is properly incorporated.
Tip the dough onto a wooden bench and knead thoroughly (eg for 5 minutes) until the dough starts to spring back – this indicates that you have developed the gluten in the dough.
Place the dough in a plastic container with a lid and leave for 2.5 to 3 hours in a warm place.
When the dough has almost doubled in size tip it back onto the wooden bench and divide into 3 equal pieces. Round each lump of dough into a ball, place in baking tins or cane proving baskets, cover with a dry tea-towel and leave in a warm place.
Build a neat platform of red bricks in the bottom of your oven to add thermal mass and preheat to 2700C - bread likes it hot!
After another 2.5 hours test the dough by poking it gently – if it springs back quickly it needs more time, if it springs back slowly it’s ready to load in the oven.
Place the tins directly on the bricks or tip the dough gently out of the cane proving baskets directly onto the bricks (called “sole baked” bread). Spray several shots of water into the oven with an atomiser gun immediately before closing the oven door – the extra steam will help to form a thicker crust.
Bake for approximately 30 minutes in tins or 18 minutes for sole baked bread. Test whether the bread is baked by turning it upside down on an oven glove and tapping the base – a hollow reverberation indicates it is baked.