To begin, finely chop the parsley and garlic and then place a small amount of the mixture plus a pat of butter onto one end of the meat.
Roll it up and skewer with a toothpick or two.
Heat a heavy bottom pot or dutch oven over high heat and pour enough olive oil to coat the bottom of the pot. Season the meat with salt and pepper and brown in batches. When they are done, remove them from the pot and set aside.
Reduce the heat to medium low and deglaze the pot with red wine, scrape up any brown bits that are stuck to the bottom of the pot and allow the wine to reduce to half.
Then, add stewed tomatoes, breaking them down with a wooden spoon.
Bring the pot to a simmer and then, add the meat back to the pot, cover and allow to simmer for 1 ½ - 2 hours until the meat is tender. Once the meat has cooked for about half an hour, taste the sauce and adjust seasoning as necessary.
Next, get started on the polenta. Bring the chicken stock to a boil in a large saucepan and season with salt and pepper.
Reduce the heat to low and slowly whisk in the polenta, being careful the grains do not stick together and form lumps.
Using a wooden spoon, stir the polenta, almost constantly for the next ten minutes, until it turns thick and creamy.
Once the polenta is fully cooked, turn off the heat and stir in the grated Parmigiano Reggiano, Mascarpone cheese and butter.
If you plan to make the polenta ahead of time, transfer it to a slow cooker and keep it warm on low heat until you are ready to serve. This will keep the polenta from firming up on you, which is what will happen if you turn off the heat and allow it to sit in the pot.
Pour the polenta onto the board, arrange the rollatini on top and spoon on the sauce.