Makes two loaves
(Ideally in the evening) Take 1 tbsp starter, add 200ml water, 100g white and 100g wholemeal flour and mix. Leave in bowl, covered with a tea towel, overnight.
(Next morning) Take 700g warm water and mix with 200g of the mix from last night. Discard the rest or use it as your starter.
Add 900g strong white flour and 100g brown flour, mix and leave for half an hour.
Add 20g salt and 50g warm water. Mix and leave for 3 hours. Turn every half hour if you can - use a hand to fold sloppy dough over itself.
Divide into two on a floured board. Leave for half an hour-an hour.
Fold into rounds and put into 2 floured bowls/proving baskets. Leave to prove for 2-3 hours.
Put round casserole dish (ideally 25cm diametre) into oven on highest heat, with lid on, about half hour before you're ready to bake.
*Put handful of brown (ideally rye) flour into casserole, to stop bread sticking to edges. Put one round into casserole, score top of loaf, put in oven with lid on, for 20 mins.
*Take lid off, put back in oven for 20 mins.
*Leave to cool on wire rack.
Put casserole dish back in oven and repeat steps with * for the second loaf.