Mix together flours, salt, yeast, and rosemary in a large bowl.

Add water and mix until combined.

Cover bowl with plastic wrap.

Let dough sit on counter for 12-24 hours.

Preheat oven and ceramic soup pot to 450.

Sprinkle flour on top of dough and dump out onto parchment paper.

Form dough into a ball shape on the parchment paper and carefully place in preheated ceramic pot.

Cook in a ceramic pan covered for 30 minutes.

Uncover and cook for an additional 10-15 minutes.

Let cool for at least 15 minutes before slicing.