100g starter + 100g strong flour + 100g water
Let sit 2-9 hours

Add 400g strong flour + 250g (ish) water + 12g (ish) salt
Mix well and adjust water as needed for a relatively dry dough
Let sit 2-20 hours

Fold/roll into a loaf
Proof in fridge 8-48 hours.

Bake 28 minutes at 260c covered in dutch oven
Bake 3 minutes 260c uncovered