Preheat your oven to 325°F.
Season the beef with salt and black pepper. In a heavy, oven-safe pot, sear the beef over medium-high heat until browned on all sides, about 2-3 minutes per side.
Add roughly chopped garlic, onion, and fresh thyme sprigs to the pot, stirring to combine flavors.
Reduce the heat, cover the pot, and allow the beef to braise slowly on the stovetop for about 20 minutes to develop deep flavor.
While the beef is braising, prepare the vegetables. Peel and cut the carrot, parsnip, and remaining onion into bite-sized pieces. Toss them with extra virgin olive oil, salt, and pepper.
After braising, add the prepared vegetables around the beef in the pot, then transfer the whole pot to the preheated oven.
Slow cook in the oven for about 1.5 to 2 hours until the beef is tender and the vegetables are roasted and caramelized.
Remove from oven, let it rest for a few minutes, then slice the beef and serve with the roasted vegetables, ensuring a delicious balance of flavors and textures.