Mix flour and 365ml of water. Leave for 2-4h to autolyse

Add starter, 15ml of water and mix in with your hands. Leave for 30min

Mix in 15g of salt with 15ml of water.

Do 4 sets of coils with 30 minutes in-between. Finish rise to 30-50%, until jiggly and domed

Shape, put in the banneton. Rest for 15min

Stitch up the top, put in the fridge for 8-24h

Preheat the oven for about an hour, with the Dutch oven to 250°

Cool for an hour+ before cutting

Bake for 25-30min, take the lid off and bake for another 20ish minutes at 220°, until desired colour