Portuguese Cornmeal Bread

In a medium bowl, stir togethercornmeal and boiling water. Placebowl in an ice-water bath and letstand, stirring mixture a few times,until cold to the touch, about 10minutes. In a large bowl, whisktogether flour, salt, sugar, andyeast. Make a well in dry mixtureand add cornmeal mixture andcold water. Stir until a wet doughforms and no dry flour remains.Cover bowl with plastic wrap andlet rise at room temperature untildough quadruples in volume andtop appears bubbly, at least 12 hoursand up to 18 hours.

Brush the bottom and sides of a 4-to-5-quart Dutch oven (about 9 1/2 inches in diameter), preferably enameled cast iron, with oil. Sprinkle generously with cornmeal and flour to ensure an even coating. With lightly oiled hands, punch down dough, pour out onto a clean work surface, and shape into a ball. Transfer to Dutch oven; lightly sprinkle top with more cornmeal and flour. Cover Dutch oven with plastic wrap and letrise at room temperature until doubled in volume, 1 1/2 to 2 hours.

Preheat oven to 500 degrees with rack in lower third. Using the tip of a sharp knife, slash top of dough in a few places to a depth of 1 inch. Lightly sprinkle top of dough with water. Cover Dutch oven with lid, transfer to oven, and reduce temperature to 450 degrees. Bake until bread is puffed and brown, 45 minutes. Uncover and continue baking until a thermometer inserted into center of loaf registers 190 degrees to 200 degrees, about 15 minutes more. Let cool in Dutch oven on a wire rack 15 minutes, then turn bread out onto rack and let cool completely, about 2 hours, before slicing and serving. (Or store, unsliced and wrapped in parchment-lined foil at room temperature up to 3 days, or sliced and frozen up to 3 months.)