Dice cheddar cheese into ¼" cubes or smaller, and/or grate with a cheese grater on the side with the larger holes.

Remove seeds and ribs from jalapeño, then chop into pieces as big or small as you want. You can even do half the jalapeño in a fine dice and half in thin slices or a larger dice if you want some variety. Add to dry ingredients.

Mix your dry ingredients (flour, salt, yeast) in a large mixing bowl. Stir to combine. Add the cheddar and jalapeño pieces and mix well.

Add lukewarm water and stir until combined. If the dough seems really dry, add a tablespoon of water and keep stirring. When you have a shaggy, sticky dough, cover the bowl and set it aside at room temp to rest for 12-18 hours (I recommend going the full 18 hours if you can).

At the end of the 18 hours the dough should have doubled or tripled in size and have a flat, bubbly top.

Preheat oven to 450°F. Place a Dutch oven inside, covered, and let preheat for 30 minutes at 450°F.

While Dutch oven preheats, generously flour a piece of parchment paper on your counter and use a plastic bowl scraper to release the dough from the sides of the bowl and onto the center of the paper.

Use floured or slightly wet hands to fold the edges of across the center of the dough to gently pull it into an oval or circle shape. This stage is messy and imprecise, that's okay. Sometimes you can fold the whole side of the dough in one move. Other times you end up zig-zagging smaller sections across the center.

Dust the surface of the dough with flour and let it sit until the Dutch oven finishes preheating.

Carefully remove the lid from the Dutch oven. Gather the corners of the parchment paper together to pick the dough up and transfer it into the Dutch oven. Put the lid back on the Dutch oven.

Bake with the lid on for 45 minutes (don't peek!), then remove the lid and bake another 10-15 minutes until deeply golden brown on top.

Transfer the fully baked loaf to a cooling rack and let cool before slicing.