Many American servicemen had their fill of mutton, coming home to declare it off-limits in the family home. This may be another reason why lamb hasn't become more popular in the States. The grass that thrives on the salty land gives the lamb meat a delicate flavor. You might want to question the chef if you find pr -sal lamb on the menu in the United States, as there is a good chance it is not authentic. The outer fat of lamb has a thin, papery covering called the fell.
Some cooks like to remove the fell, claiming it adds a strong flavor.
However, it does help in holding the shape of the leg together while roasting, as well as retention of juices and flavor. On larger cuts, I haven't noticed enough difference in flavor to warrant the extra work. On small cuts, you may wish to remove the fell before cooking. The shoulders and leg joints may also still have the musk glands attached, if not removed by your butcher. These are large yellowish pieces that you might find unsightly.