01 - Set the oven to 325°F (160°C) to prepare for braising.
02 - Pat the lamb shanks dry and season evenly with salt and freshly ground black pepper.
03 - Heat olive oil in a large Dutch oven or heavy ovenproof pot over medium-high heat. Brown the lamb shanks on all sides for 8 to 10 minutes, then transfer to a plate.
04 - Add chopped onion, carrots, and celery to the pot and sauté for 5 minutes until softened. Incorporate minced garlic and cook for 1 minute more.
05 - Stir in tomato paste and cook for 2 minutes to develop flavor.
06 - Pour in the dry red wine, scraping the pot’s bottom to loosen browned bits. Allow the mixture to simmer gently for 3 minutes.
07 - Return the browned lamb shanks to the pot. Add the stock, fresh rosemary, thyme sprigs, and bay leaves. Bring to a gentle simmer on the stovetop.
08 - Cover the pot with a lid and transfer to the preheated oven. Braise for 2 to 2½ hours, until the meat is tender and easily pulls from the bone.
09 - Remove the lamb shanks and cover to keep warm. Simmer the sauce on the stovetop for 10 to 15 minutes to reduce and thicken, if desired.
10 - Discard the herb sprigs and bay leaves, then taste and adjust seasoning as needed. Plate lamb shanks and spoon the sauce over before serving.