Combine the yeast, semolina flour, and water by pulsing 10 seconds in a large heavy-duty food processor (about 11 cup capacity) fitted with the metal chopping blade. Scrape down the side of the work bowl, recover, and let stand until foamy, about 15 minutes.
With the machine running, add 1 1/2 cups of the all-purpose flour down the feed tube. It's easier if the flour is poured from a spouted measuring cup into a wide-mouth canning funnel inserted in the feed tube, or a stiff piece of paper rolled into a cone (the opening at the bottom should be at least 1-inch across).
Using a plastic spatula scrape the work bowl and, if necessary, redistribute the dough so that it evenly surrounds the blade. Be careful of the blade. Add the salt and remaining flour, distribute evenly over the dough, and pulse for 10 seconds. Again scrape the work bowl and redistribute the dough.
Pulse the dough for 20 seconds nonstop, shut the machine off, and let the dough rest covered in the work bowl for 5 minutes. Now pulse for another 20 seconds.
Leaving the blade in place, carefully redistribute the dough until it's of uniform thickness. Recover the work bowl, keeping the pusher from the feed tube in. Note the level of the dough, estimate what it should be when doubled in bulk, and mark that level on the side of the work bowl.
Let the dough rise in the sealed work bowl until doubled in bulk, about 1 hour. Meanwhile, lightly coat an 8-inch springform pan or 8-inch pie pan lightly with nonstick cooking spray and set aside.
When the dough has fully doubled, pulse quickly 4 to 5 times to punch down, then pulse for 20 seconds nonstop. Let the dough rest in the sealed work bowl for 5 minutes, then pulse for another 20 seconds. The dough will roll into a ball and leave the sides of the work bowl reasonably clean.
Turn the dough onto a lightly floured surface, shape into a ball, then roll in the flour to dust lightly. Place the loaf in the prepared pan, cover with a clean, dry dish towel, and set in a warm, dry spot until nearly doubled in bulk, this will take about 30 minutes.
When the dough has risen for 10 minutes, position 1 rack in the middle of the oven and slide a second rack in the slot just below. Place a large shallow baking pan on the lower rack?I use a 15 1/2 by 10 1/2 by 1-inch jelly roll pan?and half-fill with water. Preheat oven to 500 degrees F.
Center the risen loaf on the middle rack and bake uncovered for 15 minutes. Reduce the oven temperature to 400 degrees F. and continue to bake until richly browned and hollow sounding when thumped, about 20 to 25 minutes longer.
Remove the bread from the pan as soon as it comes from the oven, set right-side up on a wire rack, and cool to room temperature before cutting.
Recipe courtesy Jean Anderson, Process This!, William Morrow, 2002