This whole roasted tenderloin recipe is a holiday dinner ace up your sleeve—one you can easily serve (and impress) in about an hour, including resting time, with some simple herb-roasted potatoes that can be roasted simultaneously. When dealing with tenderloin this size, variations in temperature are a given—you'll have slices ranging from rare to well, pleasing a variety of meat eaters. Once sliced, the tenderloin is sauced with a red wine reduced with red wine vinegar and shallots, then finished with a sizable knob of butter, a sauce that is simple, rich and absolutely delicious. More