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 sea salt to the dough. Mix until fully incorporated and shaggy texture forms.
03 - Stretch and fold the dough 4 times over one hour, performing folds every 15 minutes to build 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 30 minutes to ensure proper heat retention.
09 - Transfer dough to parchment paper, score the top with a sharp knife, and place in the hot Dutch oven.
10 - Bake covered for 20 minutes to create steam and oven spring.
11 - Uncover and bake for another 20-25 minutes until deep golden brown and crusty.
12 - Cool on a wire rack for at least 1 hour before slicing to allow internal structure to set.