1. Preheat oven to 325°. Season beef with salt and pepper, and heat olive oil over medium-high heat. Sear beef thoroughly on all sides, about 5-6 minutes per side, until it is a deep, mahogany brown. Transfer the beef to a plate.
2. Add garlic to pan with allspice berries and fennel seeds, and sauté for 1 minute to release fragrance. Pour in wine and scrape up bits left in the pan. Add rosemary, bay leaf, and beef broth, then add beef back to the pan and bring to a simmer. Top with onions. Cover tightly and transfer to oven.
3. Cook for 2 hours in oven. Remove pot, flip beef, and add remaining vegetables in with the meat. Cover again, and cook for an additional 45 minutes.
4. When beef is fork-tender, transfer meat to a cutting board and arrange vegetables on a large platter. Cover both with foil. Uncover pot and reduce juices on the stovetop over medium-high heat for 10 minutes, then transfer to a sauceboat. Slice roast thinly across the grain, and arrange on the platter. Serve sauce alongside beef and vegetables.