Season the beef roast with salt and black pepper on all sides.
In a large oven-safe pot or Dutch oven, heat the olive oil over medium-high heat. Sear the beef roast for about 4-5 minutes on each side until browned. Remove the roast and set it aside.
In the same pot, add the chopped onion and cook for about 3-4 minutes until softened. Add the minced garlic and cook for another minute until fragrant.
Pour in the beef broth, scraping the bottom of the pot to deglaze.
In a separate bowl, mix the cranberries, balsamic vinegar, brown sugar, thyme, and bay leaf. Pour this mixture over the beef roast in the pot.
Return the beef roast to the pot, cover with a lid, and transfer to the preheated oven.
Braise the roast for 3 to 4 hours, or until the meat is tender and easily pulls apart with a fork.
Once done, remove the roast from the oven and let it rest for 10-15 minutes before slicing.
Serve with the cranberry balsamic glaze spooned over the top.
Notes
For a thicker glaze, remove the roast after cooking and simmer the sauce on the stovetop for an additional 10-15 minutes until it reduces.
Add root vegetables like carrots and potatoes to the pot during the last hour of cooking for a complete meal.