01 - In a large bowl, mix the bread flour and water until just combined. Cover and rest for 30 minutes to allow gluten development.
02 - Add the sourdough starter and salt to the dough. Mix until well incorporated and smooth.
03 - Perform stretch and fold technique 4 times over one hour, spacing folds 15 minutes apart to build dough strength.
04 - After the final fold, gently knead in the cubed cheddar cheese and chopped jalapeños until evenly distributed.
05 - Cover the dough and let rise at room temperature for 4-6 hours, until doubled in size.
06 - Turn the dough onto a lightly floured surface. Shape into a tight round loaf and place in a floured proofing basket or bowl.
07 - Let proof, covered, for 2-4 hours at room temperature or overnight in the refrigerator for enhanced flavor development.
08 - Preheat oven to 450°F with Dutch oven inside for thorough heating.
09 - Transfer dough to parchment paper and score the top with a sharp knife or lame. Place into hot Dutch oven and bake covered for 20 minutes.
10 - Uncover Dutch oven and continue baking for 20-25 minutes until deep golden brown and crusty. Internal temperature should reach 200°F.
11 - Cool on a wire rack for at least 1 hour before slicing to allow crumb structure to set.