Make the sourdough dough as in the basic sourdough recipe.

When the stretch and folds are complete, form a loose ball and arrange in the centre of a greased 20cm x 30cm baking tin.

Finely slice the garlic, olives and potatoes before tossing in oil with the diced rosemary and salt.

Once the bulk rise is done (the dough should now fill the baking tin), top with the sliced veg and add more oil on top.

Bake at 200°C for 25 minutes, the potatoes should be cooked and golden brown.