Preheat the oven to 350 degrees F.
Spray a 2 1/2-quart or 3-quart oven-safe casserole dish with cooking spray.
Rub the chuck roast liberally with the salt and the pepper.
In a large Dutch oven over medium-high heat, add 2 tablespoons of the olive oil.
Place the chuck roast into the Dutch oven and brown well on both sides, about 4-5 minutes per side.
Transfer the chuck roast to a plate and pull off and discard the browning fat.
Add the remaining olive oil to the Dutch oven.
Add the onion, the carrot, the celery, and the pancetta to the Dutch oven and reduce the heat to medium.
Cook the onion mixture until the vegetables are tender, about 7-8 minutes.
Add the chopped garlic to the onion mixture and cook just until fragrant, about 10-15 seconds.
Add the wine to the onion mixture, bring to a boil, and cook, about 1-2 minutes.
Add the chuck roast and any accumulated juices to the onion mixture.
Add the beef broth, the tomatoes, the sliced garlic, the rosemary, the Italian seasoning, and the bay leaves to the onion mixture and bring to a gentle simmer over medium heat.
Place a layer of aluminum foil or parchment paper over the top of the Dutch oven, followed by the lid.
Cook the pot roast until the meat is extremely tender, about 2 hours 30 minutes-3 hours.
Add the chicken broth, the half-and-half, the polenta, the salt, and the black pepper to the prepared casserole dish and stir well to combine.
Place the polenta into the oven alongside the roast, uncovered, and bake, about 30 minutes.
Stir the polenta, then add the Gorgonzola and the butter, and stir again.
Bake the polenta until the cheese melts, about 10-15 minutes.
Place the roast onto a serving platter and slice or shred the meat.
Serve the polenta with the pot roast.