To prepare the steaks: bring steaks to room temperature by removing them from the fridge and letting them sit out for about 30 minutes. If using striploins, cut each steak in half to make individual portions. Pat dry, and season both sides of the steaks with salt and pepper and spread with a thin layer of dijon mustard.

To assemble the wellington: lay out 3 pieces of prosciutto ensuring that they overlap a little. (as pictured) Position the steak in the centre and top with a 4th piece of prosciutto. Fold over all of the edges making sure that the steak is fully covered by the prosciutto. Repeat until each piece is assembled. Wrap in plastic wrap and seal tightly. Transfer to the fridge and allow to chill.

Preheat the oven to 400 degrees F. Remove the puff pastry from the fridge and roll out each sheet just a little to make it smooth. Cut into 1 inch strip and wrap around the steaks 1 at a time. Be sure to overlap the pastry sheets and pinch the sides to seal. (about 3 strips per steak) Repeat until each steak is wrapped in pastry. Keep refrigerated until ready to cook. Just before going in the oven brush the top with egg wash. Cook for 18-20 minutes or until reached desired doneness. For medium rare the internal temperature will read around 130 degrees. Keep in mind that the steaks will continue to cook once removed from the oven and while cooling on a rack.

Transfer each steak onto a cooling rack and let cool 5-10 minutes.

To make the mushrooms: While the steaks are in the oven it's time to cook those mushrooms. In a large pan melt butter over medium heat. Add mushrooms and season with salt, pepper and thyme. Stir occasionally until golden brown. (about 20 minutes)

To make the blackberry sauce: In a saucepot on low add the blackberries and wine and bring to a slow boil then lower the heat and simmer until the mixture has reduced by half. Let cool and set aside.

to serve: Serve topped with mushrooms and blackberry sauce.