Mix Dough Ingredients:

In a large bowl, mix the bread flour, active sourdough starter, water, and salt using your hands or a dough whisk until no dry flour remains. The dough will be sticky; avoid adding extra flour.

Rest Dough 1 Hour:

Cover the bowl with a damp towel, beeswax wrap, or shower cap and let it rest in a warm spot for 1 hour.

First Stretch and Fold:

Using wet hands, perform the first stretch and fold: gently lift one side of the dough and fold it over itself. Repeat on all four sides. Cover and rest for 45 minutes.

Repeat Stretch and Fold:

Repeat the stretch and fold process for a total of 3 sets, resting 45 minutes between each set.

Rest Dough 10 Minutes:

After the final stretch and fold, transfer the dough to a clean countertop without adding flour. Cover with a damp towel and let rest for 10 minutes.

Spread Inclusions on Dough:

Gently stretch the dough into a rectangle. Evenly distribute half of the dried onion, jalapeños, and cheddar over the surface, pressing them lightly into the dough.

Fold and Shape Boule:

Fold one side of the dough toward the center and add half of the remaining inclusions. Fold the opposite side over and add the rest of the jalapeños, cheddar, and dried onion. Roll the dough into a ball and tuck the ends underneath to shape a boule.

Build Surface Tension:

With cupped hands, gently pull and rotate the dough across the work surface to build surface tension without tearing the bottom.

Place in Banneton:

Lightly flour a 9-inch banneton basket and place the shaped boule inside seam-side up. Pinch any open seams closed, dust lightly with flour, and cover.

Cold Ferment Overnight:

Let the dough rest at room temperature for 1 hour, then place the banneton in a plastic bag and refrigerate for a 12–24 hour cold ferment.

Preheat Dutch Oven:

The next day, place a Dutch oven with its lid in the oven and preheat to 450°F (230°C). Once preheated, keep the Dutch oven inside for an additional 30 minutes.

Score and Transfer Dough:

Remove the dough from the refrigerator and carefully invert it onto a piece of parchment paper large enough to line the Dutch oven. Score the top with one deep slash using a lame or razor blade.

Bake Covered 40 Minutes:

Carefully transfer the loaf and parchment paper into the hot Dutch oven. Cover with the lid and bake for 40 minutes.

Bake Uncovered for Color:

Remove the lid, reduce the oven temperature to 425°F (220°C), and bake for an additional 5–10 minutes, or until the crust reaches your desired color.

Cool Completely:

Transfer the bread to a wire rack and let it cool completely for at least 2 hours before slicing.

Store Leftover Bread:

Store leftovers in a bread bag once fully cooled.