If using Staub or other cast iron pan, lightly oil the surface and line with greaseproof paper.
Mix the leaven and sugar into the warm water
Put flour and salt in a large bowl, pour the wet mixture in and mix well
Bring together to form a dogh, place on a flat worktop and knead for about 10 minutes
Clean and lightly oil the bowl and place the ball of dough in, cover and leave in a warm place to ferment and double in size
Dried yeast may take 1-2 hours, natural leaven can sometimes take longer, 3-4 hours.
Take the dough out onto a floured worktop, punch out some of the air and form into a tight ball
Put the dough into the Staub, cover with a cloth and leave until it rises again - about 1 hour
Take off the cover and make a slit across the top of the dough with a sharp knife, put the lid on and heat on the hob on the lowest settingfor 10 minutes it bring it up to temperature
Still on the lowest setting, heat for a further 20 minutes
Pre-heat oven to 180c
Take off the lid, spray with a little oilve oil and place in oven for 10-15 minutes to cook and brown the top half
When cooked through, put on a cooling rack. Cool well before eating.