Now, over medium heat in a grill pan, sear the lamb shanks until golden brown.
Heat a deep saucepan; add some oil and add roughly cut leeks, celery, carrot, and onion one by one; add some whole spices, peppercorn, and bay leaf along with some fresh herbs.
Cook over medium heat until golden brown.
Now add tomato pest and cook for 2 minutes.
When you are done with mirepoix and tomato paste, add lamb stock. If you are using vegetable stock, then add some lamb jus also for rich lamb sauce.
It's time to add seared lamb shanks to the pot full of rich and aromatic stock.
Cover the stock pot with a lid and leave for 2 hours.
Until then, prepare rest everything, chop parsley, grate some cheese, and make fettuccini.
Once the lamb is done, remove from stock and shred or cut into chunks, as you desire. I prefer hand-pulled shreds.
Keep the lamb side and strain and reduce the lamb stock. Later, it's going to be used in sauce.