Heat olive oil in a large Dutch oven or heavy-bottomed pot over medium-high heat. Sear the lamb shanks on all sides until golden brown, then remove and set aside.

Add chopped onions, carrots, celery, and garlic to the same pot. Sauté until softened and aromatic, scraping up any browned bits from the bottom.

Pour in red wine, scraping the bottom to loosen browned bits. Let wine reduce slightly, then add stock, rosemary, thyme, and bay leaves.

Return lamb shanks to the pot. Cover with a tight-fitting lid and simmer gently on low heat for 2–3 hours, or until the meat is tender and falling off the bone.

Remove lamb shanks and discard herbs. Serve hot with a spoonful of the braising sauce over the top. Perfect with mashed potatoes, polenta, or crusty bread.