Ingredients

Instructions

1. 1

   Season the steaks generously with salt and pepper. Sear them in a hot skillet with 1 tablespoon of butter for just 1 minute per side to brown the exterior. Remove from heat and let cool completely.

2. 2

   In the same skillet, sauté the chopped mushrooms and shallots with the remaining butter over medium heat. Cook until all the liquid released by the mushrooms has evaporated (this is the duxelles). Stir in the thyme and let cool.

3. 3

   Brush the cooled steaks on all sides with Dijon mustard.

4. 4

   On a piece of plastic wrap, lay out two overlapping slices of prosciutto. Spread half of the mushroom mixture over the prosciutto. Place a steak in the center and use the plastic wrap to roll the prosciutto tightly around the beef. Repeat for the second steak. Chill in the fridge for 10 minutes.

5. 5

   Preheat your oven to 400°F (200°C). Cut the puff pastry sheet into two squares large enough to fully encase the beef packets.

6. 6

   Remove the plastic wrap from the beef. Place each packet in the center of a pastry square. Fold the pastry up and over to seal it completely, trimming any excess dough. Place seam-side down on a baking sheet.

7. 7

   Brush the pastry with the beaten egg and lightly score the top with a knife for decoration. Bake for 20-25 minutes until the pastry is golden brown. Let rest for 5 minutes before serving.