From Cookipedia(Redirected from Lamb fillet)
Lamb tenderloin fillet is very tender with a soft velvety texture. It is smaller than beef or pork fillet. Because of its size and tenderness it cooks very quickly and is apt to dry out if overcooked. Because, unlike pork, lamb can be eaten rare, it is better to under cook lamb than overcook it.
When cut through the backbone, the tenderloin and loin become part of lamb T-bone or loin chops.