Boscaiola Pie

1. Put the pizza stone in a gas oven on a rack about 8 inches from the broiler. Preheat the oven on bake at 500 degrees F for 30 minutes. Switch to broil for 10 minutes.
2. With the dough on the peel, spoon the Tomato Sauce over the surface and spread it evenly, leaving about an inch of the rim untouched. Distribute the mozzarella over the pie. Place the sausage in small mounds around the pizza. Arrange the mushrooms and onion evenly on top. Sprinkle evenly with the chili flakes and salt. With quick, jerking motions, slide the pie onto the stone. Broil for 3 1/2 to 4 minutes under gas (somewhat longer with an electric oven), until the top is bubbling and the crust is nicely charred but not burnt. 
3. Using the peel, transfer the pizza to a tray or serving platter. Slice into wedges and serve immediately.

Pizza Dough:

1. In a medium bowl, thoroughly blend the flour, yeast, and salt. Add the water and, with a wooden spoon or your hands, mix thoroughly. Cover the bowl with plastic wrap or a kitchen towel and allow it to rise at room temperature (about 72 degrees F) for 18 hours or until it has more than doubled. It will take longer in a chilly room and less time in a very warm one.
2. Flour a work surface and scrape out the dough. Divide it into 4 equal parts and shape them: For each portion, start with the right side of the dough and pull it toward the center; then do the same with the left, then the top, then the bottom. (The order doesn't actually matter; what you want is four folds.) Shape each portion into a round and turn seam side down (see Cook's Note). Mold the dough into a neat circular mound. The mounds should not be sticky; if they are, dust with more flour. 
3. If you don't intend to use the dough right away, wrap the balls individually in plastic and refrigerate for up to 3 days. Return to room temperature by leaving them out on the counter, covered in a damp cloth, for 2 to 3 hours before needed. Don't freeze the dough, but you can store it in the refrigerator, wrapped in plastic, for up to three days. In effect, when you're set to use it, you have your own ready-made dough. 

Basic Tomato Sauce:

1. If using fresh tomatoes, bring 4 quarts water to a boil in a 5- to 6-quart pot.
2. Cut away the dry stem area of the tomatoes, leaving the core intact. Place 2 or 3 tomatoes at a time in the boiling water for 5 to 10 seconds. Remove with a slotted spoon and put on a rack to cool. Peel the tomatoes with a paring knife. 
3. Whether using fresh or canned, cut each tomato into several wedges and run them through a food mill over a medium bowl to create a pulp (not a fine puree; you want to retain some texture). If you don't have a food mill, just squish them with your hands--it's messy but fun. 
4. Stir in the olive oil and salt. The sauce will keep, covered, in the refrigerator for up to 1 week. 
5. makes 620 to 800 grams (depending on whether you use fresh or canned tomatoes, which yield a greater volume); or enough for about 8 pizzas