Preheat the oven to 450°F.
Rub the entire pork shoulder with a tablespoon of EVOO, season the entire surface area liberally with salt and fresh ground pepper and place in the roasting pan, fat side up. Arrange the vegetables around the roast in the pan, drizzle and toss with another tablespoon of olive oil, and season with salt and pepper.
Roast the shoulder and vegetables uncovered at 450°F for 20 minutes until the vegetables beginto take color and the pork roast is browned.
Reduce the oven to 350°F.
In a large bowl, mix together the tomatoes, wine, a tablespoon of EVOO, and the rosemary leaves. Adjust the seasoning with salt and pepper. Pour evenly over the roast and vegetables in the pan. With heavy duty foil, tightly seal the roasting pan and roast at 350°F for five hours.
In a 3+ quart sauce pan heat one tablespoon of Cobrancosa. sauté the onion until translucent, about three minutes. Add the garlic and sauté for another minute. Add the broth and bring to a simmer. While stirring constantly, add the polenta in a steady stream. Continue stirring constantly for 20-25 minutes until the polenta is thick.
Add the cheese, remaining tablespoon of Corbancosa, and season with additional salt and pepper to taste. Immediately pour the polenta into a 9" x 13" baking dish and allow to cool. Refrigerate covered in plastic wrap.
Cut the polenta into squares or rectangles approximately 3" x 3" in size. Heat 2" of Cobrancosa to 350°F on a deep fry thermometer in a heavy, deep sided frying pan. Fry the polenta slices a few at a time, approximately 3-5 minutes per side until golden brown.
Serve the pork in large shreds with the sauce from the pan over the hot, crispy polenta.