I want to roast it whole, but I do think I want the center cut of the tenderloin, where fillet mignon steaks are cut from, not the butt.
I recall a recipe from the 80's where you marinate the tenderloin in garlic french dressing overnight, let it come to room temp for about 30 minuets and then roasted it in a 400 degree oven for 30 minutes, then added a can of beef broth and a large can of sliced mushroom with the liquid, and continued to roast in a 400 degree oven for another 15 minutes for rare... If you lost track of time and forgot and 30 minutes went by instead of 15, the roast would be well done! <img src="http://www.traveltalkonline.com/forums/images/graemlins/Sad.gif" alt="" /> In the 80's I did not have an instant-read thermometer.

From my notes, everyone thoroughly enjoyed it and I did only make that cut of meat for special occasions.