Preheat an oven to 375°F. Dry the beef well with paper towel and generously season on all sides with salt and pepper.
Heat oil in a large oven proof pot or Dutch oven, over medium-high. Brown the meat on all sides until deeply golden brown, 3-4 minutes per side. Transfer to a plate. Reduce heat to medium-low and add onions, celery, leeks, and garlic. Sauté until veggies are tender, about 5 minutes.
Add the wine, stock and tomato paste and bring to a simmer. Return the meat to the pan and nestle in the carrots, thyme bundle, and bay leaves; season with salt and pepper. Cover the pan and place in the preheated oven for 3 hours. Turn the meat over halfway through the cooking time. Remove the lid during the last 20 minutes of cooking to let things get nice and brown and to let the sauce reduce. When done the meat should be fork tender. Serve with the braising liquid and mashed potatoes. Enjoy!