In a large bowl, whisk together flour, rosemary, salt and yeast.
Make a well in the middle and pour in warm water. Use a spatula to combine.
Use a kitchen towel or plastic wrap to cover the bowl. Let it rise for at least eight hours. 12 is best! It should double in size and be bubbly.
Use a light sprinkling of flour on top of the dough, shape it into a slight ball and let it rise for another 30 minutes to an hour.
Sprinkle flour onto parchment paper. Use some flour to get the dough out of the bowl and onto the paper. Fold it onto itself once and shape it into a ball.
Turn the oven on to 450 degrees. Put your dutch oven inside to let it warm up, too.
After your dough has risen for another 30 minutes, take your dutch oven out of the oven and transfer your dough inside. Careful! It's hot!
Score your bread at the top in a X pattern with a knife. Close the lid and place into the oven to bake for 30 mins.
Take off the lid and let it bake for another 15 minutes to get the shell crispy.
Enjoy!! Store any uneaten bread in the dutch oven to enjoy for a few more days.