Measure water and heat for 1 minute or less in the microwave. The temperature should be between 105-115℉.
While the water warms, measure flour and salt into large mixing bowl.
Add yeast to water, stir to dissolve (no need to let it foam), then pour into mixing bowl with flour and salt.
Using the handle of a wooden spoon, stir until all of the flour is incorporated. Dough will be wet and sloppy - not kneadable, but not runny like cake batter.
Cover bowl with cling wrap or a plate and leave to let rise for 2-3 hours.
After about 1½ hours, place cast iron dutch oven with lid in oven and preheat to 450℉.
When dough is ready, lightly flour a work surface and turn the dough out on to it. Sprinkle a little more flour on top and using a dough scraper, work the dough into a ball by folding the sides inwards (about 6 scrapes).
Using oven mitts, remove the hot pan from the oven (remove the lid and place in the oven) onto a nearby trivet or stove top.
Tear off a square of parchment paper. Flip the dough ball onto the square of parchment (smooth side should be up) and then place the parchment and dough carefully into the hot pan.
Using oven mitts, take the lid from the oven and place on the pan, then put in the oven.
Bake with the lid on for 30 minutes.
Remove the lid and bake for 12 minutes more.
Carefully remove pan from the oven and let sit for 10 minutes.
After 10 minutes, the bread can be sliced and enjoyed or removed from the pan and left to cool on a cooling rack.