French Onion Beef Tenderloin is a special dinner that is easier to make than you might think! Tender slices of beef are topped with sweet, caramelized onions and melted Gruyère cheese. If you love beef tenderloin, be sure to try my Pepper Crusted Beef Tenderloin next, too!
This beef tenderloin makes a beautiful main dish for a holiday meal or a special dinner at home. Serve it for Thanksgiving or Christmas, and check out my Thanksgiving Menu and Christmas Menu for more ideas to complete your meal!
Ingredients & Substitutions
- Beef tenderloin: One whole beef tenderloin, about 4 to 5 pounds, is the star of this recipe. Trim off any excess fat and silver skin before cooking.
- Olive oil: Helps the beef brown nicely when seared. Avocado oil is another good option.
- Kosher salt and black pepper: Season the beef before searing. If using table salt, use a little less.
- Unsalted butter: Butter is used to cook the onions and finish the sauce. The cold butter stirred in at the end helps make the sauce smooth and rich. If using salted butter, reduce the added salt to taste.
- Yellow onions: Three large onions cook down until soft, sweet, and golden. Sweet onions will also work.
- Fresh thyme: Adds a light, earthy flavor to the onions and sauce. You can use about 1 teaspoon of dried thyme in place of the fresh thyme, adjusting to taste.
- Dry white wine: Adds flavor to the onions and helps lift the browned bits from the pan. Use beef broth in its place if you prefer not to cook with wine.
- Beef broth: Adds rich beef flavor to the sauce. Beef stock works, too.
- Gruyère cheese: Melts over the beef and onions for that classic French onion flavor. Swiss cheese is a good substitute.
- Fresh thyme (optional): Sprinkle a little over the finished beef for a fresh touch.
Tips For The Best French Onion Beef Tenderloin
- Let the beef sit out briefly. Take the tenderloin out of the refrigerator while you prepare the other ingredients, but don’t leave raw beef at room temperature for more than 2 hours total.
- Tie the tenderloin. Use kitchen twine to help the beef hold a more even shape and cook more evenly.
- Take your time with the onions. Cook them slowly until they are soft and golden brown. This gives the sauce its classic French onion flavor.
- Use a meat thermometer. Tenderloin can overcook quickly, so check the temperature in the thickest part of the beef.
- Let the beef rest. Resting before slicing helps the juices settle, so the beef stays juicy.
- Watch the cheese closely. Gruyère melts quickly under the broiler, so keep an eye on it to prevent burning.
FAQs
Can I make French Onion Beef Tenderloin ahead of time?
You can caramelize the onions a day ahead and store them in an airtight container in the refrigerator. When ready to serve, cook the beef fresh for the best results.
Can I use a different cut of beef?
Yes, but cooking times will vary depending on the cut and its size. Beef tenderloin is especially tender and works well for this recipe.
Do I Have To Tie The Beef Tenderloin?
Tying the beef tenderloin helps it keep a more even shape as it cooks. This helps the beef cook more evenly, especially if one end is much thinner than the other. Use kitchen twine to tie the tenderloin at regular intervals before searing.
How do I know when the beef tenderloin is done?
Use a meat thermometer to check the thickest part of the tenderloin. For medium-rare, remove it from the oven at approximately 125°F. For medium, remove it at approximately 135°F. See the food safety note in the recipe card for more information.
Do I have to use white wine?
No. You can replace the white wine with beef broth. The sauce will still be delicious!
Can I use a different cheese?
Yes! Swiss cheese is a good substitute for Gruyère because it melts well and has a similar flavor. You could also try provolone.
Can I make this recipe without a broiler?
Yes. If your oven does not have a broiler, add the Gruyère cheese over the beef and onions, then return the pan to the oven at 425°F just until the cheese melts. Watch it closely so the beef does not overcook.
What To Serve With French Onion Beef Tenderloin
French Onion Beef Tenderloin pairs well with potatoes, vegetables, and bread to soak up the rich onion sauce. Here are a few ideas to serve alongside it:
- Mashed Potatoes: Creamy mashed potatoes (or skins-on mashed potatoes) are perfect with the French onion sauce.
- Roasted Vegetables: Roasted carrots (or have you tried my air fryer carrots yet?) or roasted Brussels sprouts add a nice balance to the rich beef.
- Green Beans: Serve them simply steamed or try my roasted parmesan green beans for an easy side.
- Crusty Bread: Bread (like a French Baguette) is great for scooping up every bit of the onion sauce.
- Side Salad: A fresh green side salad adds something light to the meal.
How To Store French Onion Beef Tenderloin
Refrigerate: Store leftover beef tenderloin with the onions and sauce in an airtight container in the refrigerator for up to 3 to 4 days.
To reheat: For the best results, warm the beef gently in a covered baking dish in the oven at 300°F until heated through. Add a little beef broth if the sauce needs more moisture. Avoid overheating, as the beef can dry out.
Freeze: You can freeze leftover beef tenderloin, but the texture may change slightly. Store it in an airtight, freezer-safe container for up to 2 to 3 months. Thaw it in the refrigerator overnight before reheating.
French Onion Beef Tenderloin
Ingredients
Beef Tenderloin
- 1 whole (4 to 5 pounds) beef tenderloin, trimmed, tied
- 1 tablespoon olive oil
- 2 teaspoons kosher salt
- 1 teaspoon freshly ground black pepper
- 2 tablespoons unsalted butter, softened
French Onion Sauce
- 3 tablespoons unsalted butter
- 3 large yellow onions, thinly sliced (about 6 cups)
- ½ teaspoon kosher salt
- 1 teaspoon fresh thyme leaves
- ½ cup (120 g) dry white wine
- 1 ½ cups (360 g) beef broth
- 1 tablespoon unsalted butter, cold
- Kosher salt and freshly ground black pepper, to taste
For Finishing
- ½ cup Gruyère cheese, finely shredded
- Fresh thyme, optional, for garnish
Instructions
Prepare the Beef Tenderloin
- Remove the beef tenderloin from the refrigerator about 30 minutes before cooking.
- Preheat the oven to 425°F.
- Pat the tenderloin thoroughly dry with paper towels.
- If needed, tuck the narrow tail end underneath itself so the tenderloin is relatively even in thickness. Tie the roast with kitchen twine at approximately 1 ½-inch intervals.
- Rub the tenderloin all over with olive oil. Season evenly with salt and pepper.
Sear the Beef
- Heat a large oven-safe skillet over medium-high heat.
- Add the tenderloin and sear for 2 to 3 minutes per side, turning as needed until deeply browned all around, including the ends.
- Remove the skillet from the heat. Spread the softened butter over the top and sides of the tenderloin.
Roast the Beef
- Transfer the skillet to the oven.
- Roast for approximately 20 to 30 minutes, checking the internal temperature early rather than relying only on cooking time.
- For medium-rare, remove the tenderloin from the oven at approximately 125°F. For medium, remove it at approximately 135°F.*
- Transfer the tenderloin to a cutting board and loosely tent with aluminum foil. Rest for 15 minutes before slicing.
Caramelize the Onions
- While the beef is roasting and resting, melt 3 tablespoons butter in a large skillet over medium-low heat.
- Add the onions and ½ teaspoon kosher salt. Toss to coat the onions in the butter.
- Cook for 35 to 45 minutes, stirring occasionally, until the onions are very soft and deeply golden brown.
- Reduce the heat if the onions begin browning too quickly. If browned bits build up on the bottom of the skillet before the onions are ready, add a tablespoon of water and scrape them up.
- Stir in the thyme and cook for about 30 seconds.
Make the French Onion Sauce
- Increase the heat to medium. Add the white wine, scraping up any browned bits from the bottom of the skillet.
- Simmer for 3 to 5 minutes, or until the wine has reduced by approximately half.
- Add the beef broth. Bring to a gentle simmer and cook for 8 to 12 minutes, stirring occasionally, until the liquid has reduced and the onions are coated in a rich, concentrated sauce. The onions should not be swimming in liquid.
- Remove the skillet from the heat. Add the cold butter and stir until melted and the sauce is glossy.
- Taste before adding more salt, since the beef broth and Gruyère will contribute saltiness. Add black pepper and additional salt only as needed.
Assemble and Finish
- Preheat the broiler.
- Remove the kitchen twine from the rested beef tenderloin. Cut the tenderloin into approximately ½-inch-thick slices.
- Arrange the slices slightly overlapping on an oven-safe serving platter or in a shallow oven-safe baking dish.
- Spoon the caramelized onions down the center of the sliced tenderloin, leaving portions of the beef exposed.
- Spoon a small amount of the reduced sauce over the onions and beef. Reserve the remaining sauce for serving.
- Sprinkle the shredded Gruyère primarily over the onions.
- Broil for approximately 1 to 2 minutes, watching constantly, just until the cheese melts and develops a few golden spots.
- Garnish with fresh thyme, if using. Serve immediately with the remaining French onion sauce on the side.
Notes
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