Heat oil in a large saucepan over high heat. Season lamb shanks and cook for 5-8 minutes or until golden brown on all sides. Remove from pan. Add leek, garlic, celery, carrots and parsnips to pan, cook for 5 minutes or until soft. Add lamb shanks back to pan.

Pour in passata and chicken stock, bring to the boil, reduce heat to low and simmer, covered, stirring occasionally, for 2 ½ hours or until the lamb is tender and falling away from the bone.

Transfer lamb shanks to a bowl, cool slightly, remove the bones and shred the meat.

Add Gravox Traditional Gravy to the saucepan, whisk to combine. Add meat back to saucepan, cook for a further 2 minutes or until heated through. Taste and season with salt and pepper.

Combine parsley, garlic and lemon rind in a small bowl. Top soup with parsley mix. Serve with crusty bread if desired.