In a large bowl, combine the bread flour and lukewarm water. Mix until no dry spots remain and a shaggy dough forms. Cover and let it rest for 30 minutes (autolyse). This step helps the flour fully hydrate and gluten to develop.

Add the active sourdough starter and salt to the dough. Mix thoroughly, either by hand (squishing and folding) or with a stand mixer on low speed for 5-7 minutes, until the starter and salt are fully incorporated.

Cover the bowl and let the dough rest for 30 minutes. Perform your first 'stretch and fold': With wet hands, gently grab a portion of the dough, stretch it upwards, and fold it over itself towards the center. Rotate the bowl and repeat 3-4 more times until all sides have been stretched and folded. Cover.

Repeat the stretch and fold process every 30-45 minutes for a total of 3-4 sets. After the final set, cover the bowl and allow the dough to bulk ferment at room temperature for 3-5 hours (depending on your starter's activity and ambient temperature), or until it has increased in volume by about 30-50% and feels light and airy.

While the dough is bulk fermenting, prepare the filling. In a small bowl, melt the butter. Stir in the minced garlic, chopped rosemary, thyme, parsley, dried oregano, grated Parmesan cheese, and black pepper. Mix well and set aside.

Lightly flour your work surface. Gently turn the dough out onto the floured surface. Stretch or roll the dough into a large rectangle, approximately 12x18 inches (30x45 cm).

Evenly spread the herb and garlic butter mixture over the entire surface of the dough, leaving a small border clean on one long edge.

Starting from a long edge, tightly roll the dough into a log. Pinch the seam closed.

Using a sharp knife or dough scraper, carefully slice the log lengthwise down the middle, creating two long halves. Ensure the cut goes all the way through.

Turn the cut sides of the two halves upwards. Gently twist the two strands together, keeping the cut sides exposed to show the filling. Once twisted, bring the ends together to form a ring, pinching to seal, or simply tuck them under to form a long twisted loaf.

Carefully transfer the twisted dough onto a piece of parchment paper, or directly into a lightly floured banneton (if shaping into a round/oval for a Dutch oven, ensure it fits). If using a banneton, place the dough seam-side up. Cover the dough with plastic wrap or a damp kitchen towel.

Refrigerate for 8-12 hours, or up to 24 hours (cold proof). This develops flavor and makes the dough easier to handle.

About 1 hour before baking, place your Dutch oven with its lid in the oven and preheat to 450°F (232°C).

Once preheated, carefully remove the hot Dutch oven. If using a banneton, gently invert the dough onto a piece of parchment paper. Score the top of the loaf with a sharp razor blade or knife (optional, but can help with oven spring).

Carefully lift the dough by the parchment paper and transfer it into the hot Dutch oven. Replace the lid.

Bake with the lid on for 25 minutes. Remove the lid and continue baking for another 15-20 minutes, or until the crust is deeply golden brown and the internal temperature reaches 200-210°F (93-99°C).

If desired, brush with an egg wash during the last 10 minutes of baking for an extra glossy crust.

Carefully remove the loaf from the Dutch oven and transfer it to a wire rack to cool completely before slicing (at least 1-2 hours).