Preheat oven to 300F.
In a large, oven safe Dutch oven, brown the pancetta over medium-high heat until it is crispy and most of the fat has rendered out. With a slotted spoon, scoop out the pancetta into a bowl large enough for the roast.
Sprinkle the roast all over with salt and then lay the roast into the pot. Brown the roast on all sides for 1-2 minutes per side. Then transfer the roast to the bowl with the pancetta.
Reduce the heat to medium and add the onion, carrots, parsnips, and garlic to the pot. Saute until the vegetables soften and begin to brown, about 5 minutes.
Add the roast and pancetta back to the pot. Then add in the wine plus enough beef stock to submerge the roast half way up its side. Stir in the tomato paste and anchovy paste. Tie the thyme, rosemary, and sage with some cooking twine and add them in.
Bring the liquid in the pot to a bubble then cover the pot and put it in the oven. Braise the roast for 4 hours.
Transfer the roast and vegetable to a platter. Discard the herbs. Skim the fat off the top of the liquid and bring it to a rolling boil on high until it is reduced to 2 cups, about 15 minutes. Break up the roast into chunks (removing any pockets of fat you find) and add it and the vegetables back to the pot. Season to taste with salt and fresh ground pepper and sprinkle some parsley over the top.
Serve over polenta or mashed potatoes.