Herb Butter Finish: Top the beef with a pat of garlic-herb butter before serving for extra richness.
Make Ahead: Caramelize the onions a day ahead and reheat when ready to serve.
Wine Substitute: Use a splash of balsamic vinegar instead of wine for a non-alcoholic option.
Temperature Guide: Adjust roasting time based on desired doneness: 120–125°F for rare, 130–135°F for medium-rare, 140–145°F for medium.
This roasted beef tenderloin with French onion au jus is a restaurant-quality dish made simple at home. The tender, flavorful beef and rich, savory sauce make every bite unforgettable.
