You won't have to do much (and shouldn't) to a filet mignon to get an almost buttery piece of meat. It's lean without a ton of beefy flavor, so it's often served with sauce or wrapped in bacon to ...

Filet mignon pairs well with many flavors ... Anything fat-forward, such as browned butter and sage, a béarnaise sauce, or a red-wine reduction with cold butter, would taste great.