My favorite for beef (which is considerably easier to come by than elk) is filet mignon. Filet mignon is the tenderest part of the tenderloin cut. First, pan sear on all sides to seal in the juices. Then coat it lightly in fresh-ground peppercorns. Since you are splurging, forget the cholesterol and wrap the sides of each chunk in bacon strips. Broil if rare to medium rare. No steak is tender if overcooked. A really good cut of beef should have a fine marbling of fat running all through the grains of the meat.
For an added something, smother it in mushrooms sauteed in butter. Use chantrelles or morels if you can find them. But if they aren’t available in local specialty shops or on order from the Internet, substitute Portobellos. They are actually nothing more than the full-grown variety of the ubiquitous agaricus bisporus, or white button mushroom, so either one will do. The big portobellos just look tastier.
If he ain’t a vegitarian, he will definitely think that dinner was gooood. Best of luck on the feast.