01 - Combine bread flour and lukewarm water in a large bowl. Mix until just incorporated. Cover and let rest for 30-45 minutes to allow gluten development.
02 - Add sourdough starter and sea salt to the autolyse mixture. Mix thoroughly until fully incorporated and smooth dough forms.
03 - Perform stretch-and-fold technique every 30 minutes for 2 hours, completing 4 total sets. Keep dough covered between folds to maintain hydration.
04 - Let dough rest at room temperature for 1 hour after final fold to complete bulk fermentation.
05 - Turn dough onto lightly floured surface. Gently stretch into rectangle. Spread basil pesto evenly, leaving 1-inch border. Sprinkle 0.33 cup Parmesan over pesto layer.
06 - Roll dough into log from short end. Shape into round or batard. Place in well-floured banneton or bowl, seam side up.
07 - Cover and proof at room temperature for 2-3 hours until increased by 75%. Alternatively refrigerate overnight for 12-16 hours for deeper flavor development.
08 - Preheat oven to 450°F with Dutch oven or baking stone inside for at least 30 minutes to ensure proper heat retention.
09 - Turn dough onto parchment paper. Brush top with olive oil. Sprinkle remaining Parmesan evenly over surface. Score with sharp knife or lame.
10 - Transfer dough to preheated Dutch oven. Bake covered for 20 minutes to create steam and oven spring.
11 - Remove lid and continue baking for 18-20 minutes until golden brown, crusty, and internal temperature reaches 205°F.
12 - Transfer to wire rack. Cool completely for at least 1 hour before slicing to prevent gummy texture.