Soak the dried porcini mushrooms in warm water for about 30 minutes until rehydrated. Drain and finely chop the mushrooms. Reserve a little of the soaking liquid for later use if desired.

In a small bowl, combine the softened butter, chopped thyme, minced garlic, and lemon zest. Mix well until fully incorporated. Place the compound butter on a piece of plastic wrap and roll it into a log shape. Twist the ends to seal and refrigerate until firm, about 30 minutes.

Preheat your oven to 400°F (200°C). Season the filet mignon steaks generously with salt and black pepper on both sides.

In a large skillet, heat the olive oil over medium-high heat. Once hot, add the seasoned steaks and sear for about 3-4 minutes on each side until browned. Remove from the skillet and set aside.

In the same skillet, add the chopped porcini mushrooms and cook for 2-3 minutes until fragrant. Stir in the black truffle oil and panko breadcrumbs, mixing until well combined.

Place the seared filet mignon steaks on a baking sheet. Top each steak with the mushroom and breadcrumb mixture, pressing down gently to adhere.

Transfer the baking sheet to the preheated oven and bake for 8-10 minutes or until the steaks reach your desired level of doneness (135°F for medium-rare).

Remove the steaks from the oven and let them rest for a few minutes. Slice the compound butter into rounds and place a slice on each steak. Garnish with fresh thyme sprigs before serving.