STEPS

1. Preheat oven to 425°F.

2. Trim tenderloin roast and dry with paper towels. Sprinkle liberally with salt and pepper. Preheat pan and then heat oil over medium-high heat until heated through. Add roast, searing on all sides for one to two minutes per side. Allow tenderloin to rest. Next, roughly chop shallot and pulse in food processor. Then, add all mushrooms and stems to food processor. Pulse until mixture resembles coarse crumbs. Return skillet to heat and add mushroom mixture with a pinch of salt. Cook until all liquid has evaporated, about 5-7 minutes. Allow to cool.

3. Place a large piece of plastic wrap on counter. Lay out prosciutto slices in a rectangular fashion the same size as the surface of the tenderloin roast. Then spread the mushroom mixture over the prosciutto. Lightly dry the tenderloin roast with paper towels and then spread the 3 Tbsp. mustard over the tenderloin roast and place in the center of the prosciutto/mushroom mix. Using the plastic wrap, fold all the edges up to completely cover the surface areas of the roast with the edges of the prosciutto and mushroom mixture. Tightly wrap the entire roast in more plastic wrap and place in refrigerator for 20 minutes.

4. Unroll refrigerated Puff Pastry on enclosed parchment paper. Place a cooling rack inside a rimmed baking sheet. Remove the roast from the refrigerator and take off plastic wrap. Place roast squarely in center of puff pastry and fold over, covering all edges. Trim excess pieces and, using egg wash, seal all edges. Then rub egg wash over entire exterior. Cut 3 slits in the top of puff pastry with a sharp knife to allow steam to escape. Place tenderloin and parchment paper on top of cooling rack, and place entire baking sheet in the oven.

5. Cook for 30-35 minutes or until internal temperature on beef roast registers between 125°F and 130°F. Allow to rest 10-15 minutes before slicing thick and serving.