In a small bowl, combine the softened unsalted butter, black truffle oil, chives, parsley, minced garlic, and lemon juice. Mix well until all ingredients are fully incorporated.

Transfer the mixture onto a piece of parchment paper and roll it into a log. Twist the ends to seal. Refrigerate until firm, about 30 minutes.

Remove the filet mignon steaks from the refrigerator and let them sit at room temperature for about 30 minutes before cooking. Preheat your oven to 400°F (200°C).

Pat the steaks dry with paper towels. Generously season both sides of the steaks with coarse sea salt and cracked black pepper, pressing the seasoning into the meat.

In a large oven-safe skillet, heat the olive oil over medium-high heat until shimmering. Add the seasoned filet mignon steaks to the skillet. Sear for about 2-3 minutes on each side until a golden-brown crust forms.

Transfer the skillet to the preheated oven and roast the steaks for 5-7 minutes for medium-rare, or until they reach your desired doneness. Use a meat thermometer for accuracy (130°F for medium-rare).

Remove the skillet from the oven and let the steaks rest for about 5 minutes to allow the juices to redistribute.

Slice the chilled truffle compound butter into rounds. Place a piece on top of each filet mignon just before serving, allowing it to melt over the warm steak.

Serve the filet mignon with your choice of sides, such as roasted vegetables or mashed potatoes.