From Jim Lahey at Sullivan Street Bakery, via The New York Times
3 cups all-purpose or bread flour, more for dusting
1/4 teaspoon instant yeast
1 3/4 teaspoons salt
1. In a large bowl combine flour, yeast and salt. Add 1 5/8 cups water, and stir until blended; dough will be shaggy and sticky. Cover bowl with plastic wrap. Let dough rest at least 12 hours, preferably about 18, at warm room temperature, about 70 degrees. (I put the covered bowl of dough in my cast iron skillet that always sits on my stove...warmest spot in the kitchen.)
2. Dough is ready when its surface is dotted with bubbles. Lightly flour a work surface and place dough on it; sprinkle it with a little more flour and fold it over on itself once or twice. Cover loosely with plastic wrap and let rest about 15 minutes.
3. Using just enough flour to keep dough from sticking to work surface or to your fingers, gently and quickly shape dough into a ball. Generously coat a cotton towel (not terry cloth) with flour or cornmeal; put dough seam side down on towel and dust with more flour or cornmeal (I prefer cornmeal, adds a lovely crunch). Cover with another cotton towel, or loosely just drape the ends of the cotton towel you're already using across the top of the dough, and let rise for about 2 more hours. When it is ready, dough will be more than double in size and will not readily spring back when poked with a finger.
4. At least a half-hour before dough is ready, heat oven to 450 degrees. Put a 6- to 8-quart heavy covered pot (cast iron, enamel, Pyrex or ceramic) in oven as it heats. When dough is ready, carefully remove pot from oven. Slide your hand under towel and turn dough over into pot, seam side up; it may look like a mess, but that is O.K. Shake pan once or twice if dough is unevenly distributed; it will straighten out as it bakes. Cover with lid and bake 30 minutes, then remove lid and bake another 15 to 30 minutes, until loaf is beautifully browned. Cool on a rack. (Note: I had a big pot but no lid, so I just used some aluminum foil as the lid and it worked like a gem.)