Preheat the oven to 325°F (165°C).

Heat olive oil in a large oven-safe pot over medium-high heat. Season the beef generously with salt and pepper and sear it until browned on all sides. Remove the meat and set aside.

In the same pot, cook the chopped onion for 3-4 minutes until translucent. Add minced garlic and cook for an additional minute until fragrant.

Stir in the beef broth, tomato paste, Worcestershire sauce, thyme, rosemary, and bay leaves.

Return the roast to the pot and cover it. Transfer the pot to the oven and roast for 3-4 hours, adding the carrots and potatoes halfway through.

While the roast is cooking, boil the cubed potatoes for 15-20 minutes until tender. Drain and add butter and milk. Mash until smooth and season with salt and pepper.

Once the pot roast is finished, slice it, serve it with the carrots and potatoes, and spoon the delicious sauce over everything.