Add your active sourdough starter, water, salt, and flour to a large bowl.

Mix until everything is well combined and you have a shaggy dough. You don't need to knead it extensively.

Cover the bowl with a damp tea towel and let the dough rest for 45–60 minutes.

This rest gives the flour time to hydrate before you begin your stretch-and-folds.

After the initial rest, you'll begin your stretch-and-folds.

Do four sets of stretch-and-folds, approximately 35 minutes apart.

For each stretch and fold, gently pull up one side of the dough and fold it over itself. Rotate the bowl and repeat around the dough.

You don't need to be aggressive. The goal is simply to gradually build strength in the dough.

You'll add the jalapeños and cheddar during the fourth and final stretch-and-fold.

This is an important little step: make sure your jalapeños are very dry before adding them to the dough.

Drain the pickled jalapeños and pat them thoroughly dry with paper towels. You want to remove as much excess moisture as possible.

For the final stretch-and-fold, add some of the cheese and jalapeños as you work your way around the dough. Don't worry if they aren't perfectly distributed at first.

As you shape and fold the dough, gently press the additions into the dough with your fingers so they become incorporated without tearing the dough.

Once your stretch-and-folds are finished, cover the bowl again with your damp tea towel and let the dough continue to rise at room temperature.

This part can take anywhere from 5–10 hours, depending on the temperature in your house and even the weather outside.

You're looking for the dough to roughly double in size.

Don't get too hung up on the clock here. Sourdough fermentation is very temperature-dependent, so the dough itself is a better indicator than a specific number of hours.

Once the dough has doubled, gently turn it out onto your work surface.

Tighten the dough into a round ball, creating some surface tension as you shape it.

Try to keep the cheese and jalapeños tucked inside as much as possible, although a little cheese peeking through is definitely not the end of the world!

In fact, those little bits of cheese that make their way to the crust can become wonderfully crispy and delicious.

Place the shaped dough into a well-floured banneton basket.

Cover the basket by placing it inside a plastic grocery bag and refrigerate overnight.

I love this overnight proof because it makes the next morning so easy. The dough is already shaped, cold, and ready to bake.

The next day, preheat your oven to 450°F.

I also put my Dutch oven into the oven while it preheats so that the Dutch oven is nice and hot when the bread goes in.

When you're ready to bake, carefully turn the cold dough onto a sheet of parchment paper and score the top.

Transfer the dough to the preheated Dutch oven.

I like to add a few ice cubes underneath the parchment paper before putting the lid on the Dutch oven.

The ice creates additional steam during the beginning of the bake, which helps give the bread that beautiful crust.

It also helps keep the bottom of the bread from getting too dark.

One exception: If your dough is very cold straight from the refrigerator, I skip the ice cubes. The cold dough already provides plenty of steam as it heats up.

Bake at 450°F covered for 20–30 minutes.

Then remove the lid and continue baking for approximately 20 minutes uncovered, or until the loaf is beautifully browned and cooked through.

Keep an eye on it during the uncovered portion because the cheese can cause the crust to brown quickly.

Let the bread cool before slicing.

I know it's tempting to cut into a hot loaf of sourdough, especially when you can smell that melted cheddar, but letting it cool gives the crumb time to finish setting.