Place the flours, water and sourdough starter in a mixing bowl.

Combine until the ingredients are thoroughly incorporated, cover, and leave for 30 minutes to autolyse.

Next, add the salt and a tablespoon of water. Work this well into the dough, cover, and leave for 3-4 hours in total. Fold the dough once every hour. After the first hour, add in the cooked porridge and combine thoroughly, making sure it’s incorporated all the way throughout. Leaving the dough for an hour before adding the porridge allows the gluten to start developing first.

Once ready, the dough should feel pillowy and have increased in volume by a third.

Tip the dough out onto a lightly floured work surface and shape into a round (or your shape of preference).

Place into a floured prooving basket and leave it for one hour at room temperature. Then place the dough in the fridge overnight.

Preheat your oven to 250°C, and put your casserole pot / Dutch oven in to heat up in advance.

Flip the loaf out of the basket on to some baking parchment and slash.

Lift the loaf on the parchment paper into your hot casserole pot and place in the oven with the lid on for 30 minutes.

Carefully remove the lid and continue to bake for 15-20 minutes until you get the desired colour on the crust.

Remove the loaf and leave on a wire rack to cool for at least an hour.