Combine all ingredients except the pork belly in a non-reactive pan large enough to hold the pork belly flat.
Add the pork belly and coat it evenly on all sides. Place it back in the pan, cover, and refrigerate for 5 days, flipping and redistributing the cure during the 3rd day.
On day 6 remove the belly and rinse under cold running water. Pat dry and return to the refrigerator.
At this point the meat should be seasoned and cured. It will improve in flavor for 3-5 days in refrigeration. You can use it for cooking preparations from this point. Use or freeze within 5 days of rinsing salt cure.
Choose a large bowl that’s about five times the volume of the ingredients. Mix the flour, yeast, and water in the bowl until well combined. Cover loosely with plastic wrap and let rise at room temperature for 12 hours, or until almost tripled in volume. Now, it’s ready to use. (Keep the timing in mind. If you plan to bake bread in the morning, get the starter going early the night before.
Put the flour, starter, and water in the bowl of a stand mixer. Add the yeast. Using the dough hook, mix on low speed until everything is moist, about 4 minutes, scraping the bowl as needed with a rubber spatula. Increase the mixer speed to medium and mix until the dough clings to the dough hook, about 3 minutes more. Add the salt and mix until the dough is very soft and stretchy, another 3 minutes.
Put the dough in an oiled bowl, turning to coat it with oil. Cover with plastic wrap and set in a warm spot (90ºF) until doubled in size, about 1 hour. Scale the dough into 8oz. balls (about the size of a baseball.) Arrange balls on baking sheet and scatter a little flour on top of dough. Cover entire sheet with plastic wrap and refrigerate overnight.
Remove dough ball from refrigerator and let stand at room temperature for 1 hour. Flatten a ball on a floured work surface. Hold disk in the air and circle your fingers around the edge, pinching gently around the edge to make a border. It's easier to start stretching dough in the air instead of on a work surface, because gravity will pull and stretch it. Once it's about 8 inches in diameter, place dough on floured work surface and pat it out with your fingertips, from the center toward the edge, to fully stretch. Gently push your palms into center of the dough to stretch it toward the edges. Pat and stretch to a round about 12 inches in diameter and 1/8-¼ inch thick.
Rub the crust with olive oil, season with a little sea salt, top with ½ of the cheese, and then the broccoli rabe, peppers and pancetta and finishing with the remaining cheese.
Bake at 500F for 5-7 minutes or until the crust is golden brown, crispy and the cheese is beginning to brown.