Add all of the braised beef ingredients to a casserole dish, mix well and season with sea salt and black pepper. Put the lid on and cook at 170C/fan 150C/gas 3 for 2 1/2 to 3 hours until the meat is tender. Once tender place on the hob and simmer with the lid off to thicken the braising liquid.
Trim the sweet peppers and cut in half lengthways and then into quarters. Toss together with a drizzle of olive oil on a roasting tray and roast alongside the beef for the last 45 minutes.
In a saucepan heat the the milk and the stock together, once simmering gradually add the polenta whilst stirring continuously. Simmer on a low heat for 6-7 minutes until to fully cook through and thicken. Remove from the heat and stir through the grated cheese, butter and season, set aside.
Break up the beef using a wooden spoon and spoon over the polenta and top with roasted sweet peppers.