Before we cook lobster we take it out of its shell. Most people cook lobster in its shell, and once it's cooked there's nothing you can do to it anymore. By cooking raw lobster out of its shell you can influence its taste and texture. We cook the exterior layer of the flesh, just enough so that it will pull cleanly away from the shell, leaving the interior raw. This allows us to treat the lobster as we would raw fish. When Thomas Keller got to the French Laundry, he came up with the technique of butter poaching, which loads the flavor of butter into the lobster and cooks it so slowly and gently that the flesh remains exquisitely tender, so tender some people think it's not completely cooked. When you cook lobster violently, the meat seizes up and becomes tough, and you can't get anything into it. Gentle heating is the key to tender, flavorful lobster.