Preheat the oven to 275°F.

Cut the onion into 1-inch thick wedges. Chop the carrots into 1-inch pieces. Remove the garlic cloves from their skins and smash with the back of a knife.

Set a large Dutch oven or oven-safe pot over high heat and add olive oil.

Pat the beef dry with paper towels, transfer to a large plate, and coat on all sides with salt and black pepper.

Place the beef in the pot. Sear without moving until browned, 2 minutes. Flip the beef and sear an additional 2 minutes on the opposite side.

Remove the beef from the pot and transfer to a large plate.

Turn the heat down to medium-high. If the pot seems too dry, add the additiononal olive oil. Place the onions, carrots, and garlic in the pot and cook, stirring occasionally, until lightly browned, 3-4 minutes.

Slowly pour the red wine into the pot, gently scraping up any browned bits from the bottom. Return the pot roast to the pot and add the thyme and rosemary. Pour the beef broth over the meat.

Cover the pot and remove from the heat.

Roast on middle rack of oven until the meat is extremely tender and easily shredded with a fork, 3 1/2-4 hours.

Check to see that pot roast is done. Remove from oven or add time as needed.

Transfer the pot roast to a large serving dish. Shred the meat with two forks. Use a slotted spoon to remove the carrots from the pot, and arrange over the pot roast. Serve immediately.