01 - Mix bread flour and water in a large bowl until just combined. Cover and rest for 30 minutes to allow flour hydration.
02 - Add sourdough starter and sea salt to the dough. Mix thoroughly until fully incorporated.
03 - Perform stretch and fold technique four times over one hour, repeating every 15 minutes to build gluten strength.
04 - After the final fold, gently work cheddar cubes and chopped jalapeños into the dough until evenly distributed.
05 - Cover dough and let rise at room temperature for 4-6 hours until doubled in size.
06 - Turn dough onto lightly floured surface. Shape into a round loaf and place in a floured proofing basket or bowl.
07 - Cover and proof for 2-4 hours at room temperature, or refrigerate overnight for enhanced flavor development.
08 - Preheat oven to 450°F with Dutch oven inside for optimal steam baking.
09 - Transfer dough to parchment paper, score the top, and place in preheated Dutch oven. Bake covered for 20 minutes.
10 - Remove lid and continue baking for 20-25 minutes until deep golden brown with crispy crust.
11 - Transfer loaf to wire rack and cool for at least 1 hour before slicing to ensure proper texture.