# Ingredient list:
→ Beef
01 - 2 lb beef tenderloin, trimmed
02 - Salt and freshly ground black pepper to taste
03 - 2 tablespoons vegetable oil
→ Mushroom Duxelles
04 - 1 lb cremini or button mushrooms, finely chopped
05 - 2 shallots, minced
06 - 2 cloves garlic, minced
07 - 2 tablespoons unsalted butter
08 - 2 tablespoons fresh thyme leaves, chopped
09 - Salt and pepper to taste
→ Assembly
10 - 10 slices prosciutto
11 - 2 tablespoons Dijon mustard
12 - 1 sheet puff pastry, thawed if frozen
13 - 1 large egg, beaten for egg wash
14 - Flour for dusting
# Cooking steps:
01 - Preheat oven to 425°F
02 - Season beef tenderloin with salt and pepper. Heat vegetable oil in a heavy skillet over high heat. Sear beef on all sides for approximately 2 minutes per side until browned. Remove and let cool completely
03 - In the same skillet, melt butter over medium heat. Add minced shallots and garlic, sauté for 1 minute. Add chopped mushrooms and thyme, season with salt and pepper, and cook until all moisture evaporates and mixture reaches paste-like consistency, approximately 10 minutes. Transfer to a bowl and let cool
04 - Lay a large sheet of plastic wrap on work surface. Arrange prosciutto slices in slightly overlapping layer to form a rectangle just larger than the beef
05 - Spread cooled mushroom duxelles evenly over the prosciutto layer
06 - Brush the cooled beef with Dijon mustard
07 - Place mustard-coated beef on the center of the duxelles-covered prosciutto
08 - Using the plastic wrap as an aid, roll prosciutto and mushroom duxelles around the beef into a tight log shape. Twist the ends of the plastic wrap to seal the bundle and refrigerate for 20 minutes
09 - Roll out puff pastry on a floured surface to a rectangle large enough to fully encase the beef. Unwrap beef from plastic wrap and place in the center of the pastry sheet
10 - Fold pastry over beef, trimming any excess. Seal edges by pressing together and place seam-side down on a parchment-lined baking sheet
11 - Brush pastry with beaten egg wash. Decorate with pastry scraps if desired. Chill for 10 minutes
12 - Bake for 40 to 45 minutes until pastry is golden brown and an instant-read thermometer inserted into the beef center reads 120°F for rare or 130°F for medium-rare
13 - Remove from oven and let rest for 10 to 15 minutes before slicing