This is one of my standby meals when pork filets go on sale. It's from Jacques Pépin's Table, which I think was my first cookbook. Pépin does it all in this book, not only supplying heaps of great recipes but combining the individual dishes into menus to which he suits specific wines. If you can't find a copy in print, here's the webpage with the recipe for Filet of Pork Charcutière.
(In my experience, the flavours are so forward in this dish that chasing after some of the specific ingredients he lists is unnecessary. Use any onion, though red onion is a treat, and frankly, the white wine is not essential. Pickles, tomatoes and Tabasco are the integral components.)
I doubt Pépin makes even one suggestion for a Douro, a Dão or an Alentejo in the entire cookbook, but that's what I've got decanted in the pitcher above. After reading over his notes, a red from Portugal makes even more sense now than when I served it. The deli-style sauce is acidic so you need wine that won't turn to flab by comparison. I hate to say it, but no effing Merlot. A Barbera, or another rustic Italian red might work nicely but I think a lusty red from Portugal is ideal.