01 - Combine bread flour and water in a large bowl. Mix until just incorporated, cover, and let rest for 30-45 minutes.
02 - Add sourdough starter and sea salt to the dough. Mix thoroughly until fully integrated and dough begins to develop structure.
03 - Perform stretch-and-fold sets every 30 minutes for 2 hours (4 sets total). Keep dough covered between folds to prevent drying.
04 - Let dough rest at room temperature for 1 hour after completing the final stretch-and-fold set.
05 - Turn dough onto lightly floured surface. Gently stretch into rectangle. Spread pesto evenly, leaving 3/4-inch border. Sprinkle 1/4 cup Parmesan over pesto layer.
06 - Roll dough into tight log from short end. Shape into round boule or batard, ensuring seam is secure.
07 - Place dough seam-side up in well-floured banneton or bowl lined with floured towel. Cover and proof at room temperature for 2-3 hours, or refrigerate overnight for 8-12 hours for enhanced 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 out onto parchment paper. Brush surface with olive oil and sprinkle remaining Parmesan. Score with sharp knife or lame.
10 - Transfer dough to preheated Dutch oven. Bake covered for 20 minutes to create steam and develop oven spring.
11 - Remove Dutch oven lid. Continue baking for 18-20 minutes until crust is deep golden brown and sounds hollow when tapped on bottom.
12 - Transfer loaf to wire rack. Cool completely for at least 1 hour before slicing to ensure proper crumb structure.