Ingredients:
For the Beef Tenderloin:
1 (4-5 pound) beef tenderloin, trimmed
2 tablespoons olive oil
4 cloves garlic, minced
2 tablespoons fresh thyme leaves
Kosher salt and black pepper
2 cups beef broth
1 cup water
For the French Onion Au Jus:
4 tablespoons butter
2 large yellow onions, thinly sliced
1 tablespoon fresh thyme leaves
2 cloves garlic, minced
1 teaspoon brown sugar
1 tablespoon Worcestershire sauce
2 cups beef broth
Kosher salt and black pepper
Instructions:
Prepare the Beef Tenderloin:
Remove the beef tenderloin from the fridge 1-2 hours before roasting to bring it to room temperature. Preheat your oven to 475°F (245°C).
Rub the beef with olive oil, minced garlic, thyme leaves, and generously season with kosher salt and black pepper.
Sear the Beef:
In a large oven-safe skillet, heat a bit of olive oil over high heat. Add the beef tenderloin and sear on all sides until browned, about 2-3 minutes per side.
Roast the Beef:
Transfer the skillet with the beef tenderloin to the preheated oven. Roast until the internal temperature reaches 120-125°F (49-52°C) for medium-rare, approximately 25-40 minutes, depending on the size of the roast.
Remove from the oven, transfer the beef to a cutting board, cover with foil, and let it rest for 10 minutes before slicing.
Prepare the French Onion Au Jus:
While the beef rests, melt the butter in the same skillet over medium-high heat. Add the sliced onions, thyme, and garlic. Cook, stirring occasionally, until the onions are caramelized, about 15 minutes.
Add the brown sugar and Worcestershire sauce, stirring to combine, and simmer until reduced by half.
Add the beef broth, and bring to a simmer. Season with salt and pepper to taste. Let it cook for another 10 minutes.
Serve:
Slice the rested beef tenderloin and serve with the French onion au jus.
Notes:
You can prepare the beef tenderloin ahead by seasoning it and storing it in the fridge. Bring it to room temperature before roasting.