1-Preheat oven: Preheat oven to 180°C (350°F).

2-Pat lamb shanks dry: Pat lamb shanks dry, then season with salt and pepper.

3-Heat olive oil and brown lamb shanks: Heat 2 tablespoons olive oil in a heavy pot over high heat and brown lamb shanks for about 5 minutes in batches. Remove and set aside.

4-Sauté onion and garlic: Reduce heat to medium-low, add remaining olive oil, sauté onion and garlic for 2 minutes.

5-Cook carrot and celery: Add carrot and celery and cook for about 5 minutes until onions are translucent and sweet.

6-Add liquids and herbs: Pour in red wine, chicken stock, crushed tomatoes, tomato paste, thyme, and bay leaves; stir to combine.

7-Return lamb shanks to pot: Return lamb shanks to pot, submerging most of the meat in liquid.

8-Simmer and cook in oven: Bring to simmer on stove, cover, and transfer to oven. Cook 2 hours.

9-Cook uncovered: Remove lid and cook uncovered for 30 minutes or until lamb is fork-tender; if needed, cover and continue cooking.

10-Remove lamb and discard herbs: Remove lamb shanks and keep warm. Discard bay leaves and thyme.

11-Strain sauce: Strain sauce by pressing vegetables into a bowl, then return sauce to pot.

12-Simmer sauce: Simmer sauce to reduce to desired thickness. Season with salt and pepper.

13-Serve: Serve lamb shanks over mashed potatoes, polenta, or pasta topped with sauce and fresh thyme garnish if desired.