when it comes to beef tenderloin i am a purist. like justb said, some salt and pepper are perfect. maybe a little bit of olive oil to help browning and some garlic. but you really don't need much. for serving i usually just give everyone a little bit of garlic butter to melt on top.
if you bought a whole PISMO (Packaged indivudually side meat on), i like to trim all the fat, cut off the chain meat, and top roast, and make filet mignon out of the the actual tenderloin while reserving the chain meat for cheese steaks, and the top roast for stuffing with herb and blue cheese and braising.
all in all though, i like to let the flavor and texture of beef tenderloin have the spotlight. in my opinion there is no finer cut of meat. perhaps served with a baked potato and some asparagus, wrapped in prosciutto and grilled, topped with just a little bit of hollandaise.
enjoy.
