Start with a large bowl and a wooden spoon, and add your flour to the bowl. Measure the yeast and add it to one side of the bowl. Measure the salt and add it to the other side.
Using a wooden spoon, stir the yeast into the flour on its side of the bowl first and then stir the salt into the flour on its side of the bowl. This will prevent the salt mixing directly with the yeast. Give the whole mixture a few good stirs to make sure everything is combined.
Add the sharp cheddar cheese and the sliced jalapenos to the flour mixture and stir until well coated and evenly distributed.
Once the dry ingredients are combined, measure the water. Make sure the water is at room temperature; water that is too warm or too cold can kill the yeast and prevent the bread from rising at all. Pour the water in and stir with a wooden spoon. The dough will be rough and a bit sticky, but that's normal.
Stir until all the flour is combined. This is not normal bread dough (there's no kneading involved in this recipe), so you don't need to be too concerned about the appearance of the dough at this point. Just make sure the ingredients are combined well.
Cover the bowl with plastic wrap. It's a good idea to ensure there's adequate space left in the bowl for the dough to at least double in size. Place the bowl in a warm, draft-free place and let it rise for 12-18 hours.
After the dough has risen for 12-18 hours, preheat oven to 450 degrees Fahrenheit. Place your Dutch oven with the lid on in the cold oven and let it heat up with the oven.
Place a piece of parchment paper on the counter and dust it with flour. Rub flour on your hands and scrape the dough away from the sides of the bowl, gathering it in your hands as best you can (it may feel kind of fluid and not at all like regular bread dough) and forming it into a circular loaf on the parchment paper. Don't worry if it still looks a little rough in places. This lends to the rustic look of this loaf.
Once you have it shaped, the dough needs to undergo a second rise (much shorter than the first). The goal is to handle the dough as little as possible at this stage because any amount of tugging at the rough can cause it to deflate after it has undergone its second rise. The next few steps will help prevent this. But don't worry if it deflates a bit. This bread dough is pretty forgiving.
Sprinkle flour over the top of the loaf and loosely cover it with plastic wrap to prevent a skin from forming over the dough. The flour also prevents the plastic wrap from sticking to the dough so when you take it off at the end of the rise, it doesn't disturb the dough and wreck the rustic shape you've created. Let the dough rise for about 45 minutes. Your oven will also be preheating during this time (and so will your pot).
Once 45 minutes have passed remove the plastic wrap from the dough and trim the parchment paper into a circle closely around the dough. If it doesn't look like the dough has risen that much, don't worry about it. The loaf will puff up a bit when it hits the heat of the oven.
Remove the preheated pot from the oven and transfer the dough into the pot as carefully as possible by handling only the parchment paper. Place the lid on the pot and return it to the oven for 30 minutes. Don't open the oven during this time, and certainly don't take the lid off the pot; the crispness of the crust develops because of the steam that builds up in the pot during this 30 minutes.
After 30 minutes have passed, remove the lid from the pot and continue baking for another 15 minutes. After the 15 minutes have passed, remove the pot with bread from the oven and place it on a wire rack to cool. You'll probably hear it crackling as it cools - this is normal.
If you can, resist the urge to cut into the bread until it has pretty much cooled completely. The bread continues to bake on the inside even after it has been removed from the oven and cutting it too early could result in the inside becoming gummy or rubbery.