In a large bowl, whisk together honey and water. Sprinkle with yeast and let sit for 10-15 minutes.
Add flour, oats and salt and stir together with a rubber spatula just until combined. The dough will look a little sticky and stringy and there should still be a little flour around the edges of the bowl.
Cover and let rise somewhere warm (see note below) until it has doubled in size, about 8-10 hours.
Once the dough has doubled in volume, use your hands (or a dough scraper if you have one) to pull the dough out onto a floured surface. With floured hands, gently fold the dough into itself several times until a soft, flour-covered ball is formed. Seam side up, lift and place it into a flour dusted bowl. Dust with flour, cover and refrigerate overnight. You can even leave it for as long as 48 hours at this point if you’re not able to bake it right away.
When you're ready to bake your bread, preheat oven to 450ºF (232ºC) with a 4 to 6-Qt Dutch oven inside the oven.
Once the oven is preheated, uncover then invert the bowl to turn the dough out onto a lightly floured surface seam side down. Turn and fold it into itself a few times just until you've nudged it into the shape of a loaf. Lightly brush the dough with filtered water and sprinkle remaining oats across the top and sides, gently pressing them into the surface. Place loaf on a sheet of parchment paper and score the top with a razor blade or the tip of a sharp knife with a design of your choosing. This will allow steam to escape while it’s baking.
Remove the Dutch oven from the oven and transfer the dough, still on the parchment, into the Dutch oven. Cover and bake for 30 minutes, then remove the cover and bake for 15 minutes more. Your bread will be done once the top is browned, and it sounds hollow when you tap the top.
Using parchment edges, lift bread from Dutch oven and transfer it to a wire cooling rack to let cool for up to an hour before slicing.