Pat the beef roast dry with paper towels and season generously with salt and black pepper on all sides.
Heat olive oil in a Dutch oven over medium-high heat until shimmering. Sear the beef for 4 to 5 minutes per side until deep golden brown. Remove and set aside.
Reduce heat to medium and add chopped onion. Saute for 5 minutes until softened, scraping up browned bits from the bottom.
Stir in minced garlic and cook for 1 minute until fragrant.
Pour in balsamic vinegar and scrape the bottom of the pot with a wooden spoon to release all browned bits.
Stir in beef broth and brown sugar until sugar dissolves. Return the seared beef to the pot.
Scatter whole cranberries, fresh thyme sprigs, and carrots (if using) around the roast.
Cover with lid and transfer to preheated 325°F oven. Braise for 3 to 3.5 hours until fork-tender.
Remove roast from pot and let rest on cutting board for 10 minutes.
Skim fat from sauce. For thicker glaze, simmer on stovetop for 5 to 10 minutes or add cornstarch slurry (1 tablespoon cornstarch mixed with 2 tablespoons water).
Slice or shred the beef and arrange on serving platter. Spoon warm cranberry balsamic glaze generously over the top.
Notes
Chuck roast is best for this recipe because of its marbling and tenderness when braised. Brisket or bottom round can substitute but may need longer cooking time.
Frozen cranberries work just as well as fresh – no need to thaw first.
For best flavor, make this a day ahead. The taste improves as flavors meld together overnight.
Leftover beef can be shredded and used for sandwiches, tacos, or pasta dishes.
Nutrition
Serving Size:1 serving (about 6 oz beef with glaze)