In the bowl of a stand mixer fitted with the paddle attachment, combine flour, instant sourdough yeast, and salt. Add 1 3/4 cups (420g) warm water, and beat at medium-low speed until a sticky dough forms, about 30 seconds. Cover bowl and let rise in a warm, draft-free place (75°F/24°C) for 2 hours. Then refrigerate for at least 2 hours, and up to 18 hours.
Line a sheet pan with parchment paper, and generously dust with bread flour.
Turn out dough onto a floured surface. Gently stretch and fold bottom third over to center. Stretch right side out, and fold right third over to center; repeat with left side. Finish by folding top third over previous folds. Roll loaf away from you, and using both hands, cup dough and pull it toward you to seal. Turn dough 180 degrees, and pull again until a tight, smooth, oval boule forms. Place dough seam side down on prepared pan. Cover and let rise in a warm, draft-free place (75°F/24°C) for 1 hour. (Alternatively, place dough on prepared pan; cover and refrigerate overnight. The next day, remove dough from refrigerator, and let rise in a warm, draft-free place [75°F/24°C] for 1 hour.)
When dough has 30 minutes left to rise, place a 5- to 7-quart oval enamel-coated Dutch oven and lid in cold oven. Preheat oven to 500°F (260°C).
Using a lame or razor blade, score top of loaf. Carefully remove hot Dutch oven from oven; remove lid, and place dough, still on parchment, in Dutch oven. Cover with lid, and place back in oven.
Immediately reduce oven temperature to 425°F (220°C). Bake for 30 minutes. Remove lid, and bake until an instant-read thermometer inserted in center registers 205°F (96°C), 10 to 15 minutes more. Immediately remove loaf from Dutch oven, and let cool completely on a wire rack.