Feed your starter 3-4 hours prior to making the bread.
In a bowl, mix water and starter with a dough whisk or your hands.
Add bread flour to the starter mixture and combine well until it's a shaggy dough. The dough should be sticky.
Add salt and use the pincer method to combine. This is done by squeezing the dough between the thumb and fore finger (wet your hands so they don't get as sticky), Fold it in half and pinch it again. Cover and let rest 20-30 minutes.
Complete one set of stretch and folds by gently pulling a section of dough up and folding it toward the center. Rotate the bowl a quarter turn and repeat at the 12, 3, 6, and 9 positions. Cover and let rest for 30 minutes and then complete two more rounds of stretch and folds every 30 minutes (this will help strengthen the dough to hold its shape).
During the final stretch and fold, gently sprinkle in the drained jalapenos and cheddar cheese, folding the dough one final time to incorporate. Then cover bowl with a towel and let ferment for 1 1/2 to 2 hours at room temperature (75°F), or until almost doubled.
Dust counter with a little flour. Shape the dough into a boule (round loaf). Shape the dough by gently pulling it toward you, keeping the fillings tucked inside as much as possible. If a little cheese peeks through, that’s okay. Remove any jalapeños sticking out to prevent burning.
Dust a bread proofing basket (or banneton) with flour and place the dough top down into the banneton. Pinch seam together. Dust top with flour and cover with plastic wrap. Place in the fridge to cold proof for 12 to 18 hours.
Preheat Dutch oven at 457° F for at least 30 minutes.
Remove dough from fridge, and turn onto parchment paper. Score and place in hot dutch oven. Do this quickly so the dough does not sit at room temperature long. Turn down the temp to 450° F. Bake for 20 minutes with the lid on. Remove the lid and bake, uncovered, for 15-20 minutes, or until the top is golden brown or the internal temp has reached 210°F.
Remove bread from Dutch oven and rest on a cooling rack at least 1 hour before slicing.
Notes
Drain the jalapeños well and place on a paper towel before adding. You can also dice up fresh. For a spicier loaf you can leave the seeds.Use 1 cup freshly shredded sharp cheddar for the best flavor. I prefer the Tillamook brand. Storage - Store in a linen bag, a paper sack, or a bread box and it will remain fresh for 2-3 days.