Position a rack in the lower third of the oven and preheat to 325 degrees F. Heat the olive oil in a Dutch oven over medium-high heat. Season the meat with salt and pepper and sprinkle with the flour; add to the pot and cook until browned, about 5 minutes per side. Remove from the pot.
Add the bacon, onion and chopped carrots to the pot; cook, stirring, until soft, about 5 minutes. Add the tomato paste and garlic; cook, stirring, until the paste starts to sizzle, about 4 minutes. Stir in the cognac, scraping up any browned bits from the bottom of the pot. Add the wine and broth, then return the meat to the pot.
Put the celery, bay leaves, peppercorns, allspice, cloves and herb sprigs on a square of cheesecloth and tie into a pouch with kitchen twine; add to the pot and bring to a simmer. Lay a round of parchment paper on the surface of the meat and cover with the lid. Transfer the pot to the oven and cook 1 hour, 30 minutes. Turn the roast, then add the rutabaga, potatoes, halved carrots and 1 teaspoon salt. Cover with the parchment and lid and return to the oven until the meat is fork-tender, 1 hour, 30 minutes, to 2 hours more. (A meat thermometer should register 185 degrees F.)
Transfer the vegetables to a plate using a slotted spoon and transfer the roast to a cutting board. Make the gravy: Remove the herb pouch and skim off the fat from the cooking liquid; simmer the liquid over medium heat until reduced by half, about 25 minutes. Season with salt and pepper. Return the vegetables to the gravy.
Untie the roast, thinly slice against the grain and arrange on a platter. Spoon the vegetables and gravy over and around the meat. Sprinkle with the chopped parsley.