Sear the whole tenderloin in olive oil on every side and season. Cool down. Clean and finely chop the mushrooms. Sweat them in butter and cook until all the water has evaporated seasoning. Cool down. Mix the duxelle of mushroom with the foie gras mousse gently. Cover the cold tenderloin with the duxelle.

Roll the puff pastry to get a sheet 12 x 36 inches and a ½ inch thick. Brush the edge with egg wash. Place the tenderloin in centre and wrap everything. On a cookie tray cook the tenderloin at 375°F for 35 minutes in the center of the oven.

Let the tenderloin rest for 5 minutes then cut the portion and serve with the sauce of your choice.