Kosher salt and freshly ground black pepper to taste
3 egg yolks
1 tbsp lemon juice
1/2 cup clarified butter, melted
1 tbsp fresh tarragon, chopped
1 tbsp fresh chervil, chopped
1 tbsp fresh parsley, chopped
1 shallot, minced
1/4 cup white wine vinegar
1/4 cup dry white wine
Instructions
Preheat oven to 425°F. Pat the beef tenderloin dry with paper towels and season generously with salt and pepper.
In a large oven-safe skillet, heat butter and olive oil over high heat. Add the beef and sear on all sides until deeply browned, about 2 minutes per side. Add thyme and garlic to the pan.
Transfer the skillet to the oven and roast for 20-25 minutes for medium-rare (internal temperature 125°F). Remove from oven, tent with foil, and let rest 10 minutes.
While the beef rests, make the Béarnaise sauce: In a small saucepan, combine minced shallot, tarragon, chervil, white wine vinegar, and white wine. Simmer over medium heat until reduced to about 2 tablespoons. Strain and let cool.
In a heatproof bowl, whisk egg yolks and lemon juice until thick. Place bowl over a pot of simmering water (double boiler) and whisk constantly. Slowly drizzle in melted clarified butter while whisking until sauce thickens. Remove from heat and stir in the herb reduction and chopped parsley. Season with salt and pepper.
Slice the rested Chateaubriand into 1-inch thick medallions. Serve immediately with Béarnaise sauce on the side.
Tips
For best results, let the beef come to room temperature for 30 minutes before cooking.
Use a meat thermometer to ensure perfect doneness.
Leftover Chateaubriand can be sliced thin and used in sandwiches.