Prepare to Bake. About an hour before baking, place a pizza stone in the middle of the oven and preheat to 450 °F / 232 °C. Prepare to steam the oven using your regular method (such as tossing ice on a preheated sheet pan) or set out a deep, oven-proof rectangular pan to cover the loaf and create a steam chamber.
Slash and Bake with Steam at 450 °F / 232 °C. Gently invert the loaf onto parchment or a floured peel. Brush excess flour from the top and sides of the loaf. Using a baker’s lame or serrated knife, slash in one long line or two slightly angled lines.
Slide the bread onto the hot pizza stone and steam the oven or cover the loaf. Bake for about 40 minutes, until the crust turns deep golden brown and the internal temperature reaches about 205 °F / 96 °C. After 20 minutes of baking, turn the loaf to facilitate even browning and remove the cover or steam pan. Cool to lukewarm before slicing.