Preheat your oven to 325°F (160°C).
Pat the beef knuckle dry with paper towels and score any fatty areas with a sharp knife.
Rub the entire surface with olive oil, then generously coat with salt, pepper, and crushed caraway seeds.
Use a small knife to make slits in the meat and tuck the halved garlic cloves inside.
Place the onion and carrots in the bottom of a roasting pan or a parchment-lined baking sheet.
Position the beef on top of the vegetables and pour the dark beer into the bottom of the pan.
Top the beef with fresh rosemary sprigs and roast uncovered for 3 hours, basting with pan juices every 45 minutes.
Increase the oven temperature to 425°F (220°C) and roast for another 20-30 minutes until the exterior is deeply browned and crispy.
Remove from the oven and let rest for 15 minutes before carving.