In a large skillet, melt the butter over medium heat. Cook the lamb shanks, garlic and thyme for 4 to 5 minutes, regularly basting the meat with the butter until golden.
Transfer the shanks and garlic into a slow cooker.
In the same skillet, cook the onion, carrots and celery for 2 to 3 minutes.
Add the red wine and let simmer until the liquid has reduced by half.
Add the veal stock and tomato paste and stir.
Pour the veal stock mixture over the shanks. Cover and cook for 7 to 8 hours on low, until the meat falls easily off the bone.
Remove the shanks and keep warm.
With a fine sieve, filter the sauce above a pan. Bring the sauce to a boil and simmer for 15 to 20 minutes over low heat until it has reduced by half.
Serve the shanks with the sauce.
Chef’s Tip
Sear the shanks well and baste regularly with the flavoured butter before placing them in the slow cooker.
