Ingredients (1 loaf):
100g leaven (50:50 flour-water - from sourdough starter)
(500 grams flour I suggest this mix, but can vary proportions)
150g Organic Three Malts and Sunflower Brown Flour
100g Swiss Dark flour (can substitute bread flour if unavailable)
50g wholemeal flour (can vary based on what you like)
200g bread flour
25g warm water
mix the leaven with water, add flours and mix well. Cover bowl and leave for a couple of hours to autolyse. Dissolve salt in warm water and add to dough and briefly knead to encorporate. Cover bowl and return to fold dough every half hour or so. After a couple of hours, form dough into a loaf and place in a well-floured proving basket (for better release, I like to use rice flour). Flour top of loaf and cover or place in a plastic bag. Refrigerate overnight or for up to two days.
The loaf will be based in a large pot, like a Le Crueset casserole (Dutch oven). Place the pot in your oven and heat to 250C . Make sure the oven has reached full temp and has had time to heat the pot. When you reach temp, carefully add the loaf to the pot (I tilt the pot and carefully overturn the basket into the pot). Slash the loaf, cover and return to oven. After 30 minutes, remove cover from the pot, lower the oven temp to 200C and bake until it looks done.
You can play around with the proportions of the flours to achieve something you like.