Add <quantity>270<unit>g</unit></quantity> of toasted rolled oats and <quantity>400<unit>ml</unit></quantity> of water to a bowl. Let it soak for 30m to hydrate

Add <quantity>730<unit>ml</unit></quantity> of water and <quantity>1<unit>kg</unit></quantity> of stone-ground sifted bread flour to the bowl of a stand mixer

Add <quantity>100<unit>g</unit></quantity> of stone-ground wholemeal flour. Mix with the hook attachment on medium-low speed until fully combined, scraping down the sides as needed

Cover with cling film and refrigerate for 30m to 24h to hydrate. The longer it sits, the more flavorful and lighter the bread will be

Add <quantity>20<unit>g</unit></quantity> of salt and <quantity>200<unit>g</unit></quantity> of sourdough starter

Mix with the hook attachment for 4m on low speed until everything is combined, scraping down the sides as needed

Turn up the speed to high and knead for 4m until the dough starts to pull away from the sides of the bowl to form a ball

Transfer the dough to a bowl, gently lifting it up to fold one side underneath itself. Repeat on all sides to form a loose ball and cover with cling film. Let it proof for 45m at room temperature to double in size

Add the hydrated oats. Fold the dough onto itself all around to incorporate the oats. Cover and proof for 45m at room temperature to double in size

Remove the cling film and repeat the process of folding the dough onto itself. Cover it and let it proof for 45m at room temperature

Transfer the dough to a work surface dusted with all-purpose flour and divide it in two parts

Fold each part onto itself. Cover and proof them for 45m at room temperature to double in size

Dust <quantity>2</quantity> bannetons with all-purpose flour and add rolled oats to taste on the base, which will be the top of the bread

Transfer each dough to a banneton, twisting their ends to seal them. Refrigerate overnight to slow proof

Turn the oven to <temperature>240<unit>°C</unit></temperature> and preheat two dutch ovens or heavy-bottomed pots

Transfer the loaves to a piece of parchment paper and score them with a pair of scissors or a bread lame

Place <quantity>1</quantity> loaf, with the parchment paper, inside a preheated dutch oven and cover it. Repeat with the other loaf

Place the dutch ovens in the preheated oven and lower the temperature to <temperature>210<unit>°C</unit></temperature>. Bake for 20-25m until they start to rise

Remove the lids and finish baking at <temperature>210<unit>°C</unit></temperature> for another 20m until a nice golden crust has formed

The oat bread is ready! Enjoy!