01 -
Pulse the mushrooms in a food processor until they reach a fine, breadcrumb-like consistency. Heat a tablespoon of olive oil in a large skillet over medium heat, then sear the beef tenderloin on all sides until beautifully browned. Set aside on a cooling rack.
02 -
In the same pan, add remaining olive oil and butter. Sauté the diced onions and minced garlic until aromatic and translucent. Add the processed mushrooms and cook patiently for 10-15 minutes until the mixture becomes dry and concentrated. Stir in fresh thyme leaves and let everything cool completely.
03 -
Preheat your oven to 400°F (200°C). On a lightly floured surface, roll the puff pastry into rectangles about ½ cm thick. Layer the prosciutto slices over the pastry, slightly overlapping each piece. Spread the cooled mushroom mixture evenly over the prosciutto, then place the seared beef on top.
04 -
Brush the pastry edges with beaten egg wash, then carefully fold the pastry around the beef, pressing the seams firmly to seal. Place seam-side down on a greased baking sheet, brush the entire surface with egg wash, and chill in the refrigerator for 25 minutes.
05 -
Bake for 22-25 minutes until the pastry is golden and puffed, and the internal temperature reaches 125-130°F for perfect medium-rare. Allow to rest for 10 minutes before slicing to let the juices redistribute beautifully.