In a large mixing bowl, combine 4 cups of bread flour and 1 teaspoon of salt. In another bowl, mix 1 cup of sourdough starter with 1 ½ cups of warm water until smooth. Gradually combine the wet mixture with the dry ingredients, stirring until a rough dough forms.

Transfer the rough dough onto a floured surface and knead for about 8–10 minutes until it's smooth and elastic. Shape it into a ball, place it in a lightly greased bowl, cover with a cloth, and let it rest at room temperature for 4–6 hours, or until doubled in size.

Flour your work surface and roll the dough into a 12x16-inch rectangle. Spread a layer of pizza sauce, leaving a 1-inch border. Sprinkle mozzarella cheese and sliced pepperoni, then roll the dough tightly from the long edge, pinching the seam to seal.

Place the rolled dough seam side down on a parchment-lined baking tray. Make diagonal slashes on the top, leaving about ½ inch uncut. Gently pull apart the slices to reveal the filling. Cover and let it rise for an additional 30-45 minutes.

Preheat your oven to 400°F (200°C). Brush the top with olive oil and sprinkle with herbs. Bake for 30–35 minutes, or until golden brown and hollow when tapped.

Once baked, remove from the oven and transfer onto a wire rack. Allow to cool for at least 10 minutes before slicing.