Prosciutto & Mascarpone Beef Wellington with Port Wine Chocolate Reduction Sauce

Preheat oven to 400 F with the rack in the center.

Pat beef dry and generously season it with sea salt and fresh ground pepper on all sides. Rub beef all over with olive oil. Heat a large skillet on high heat (preferably a cast iron skillet) and lightly coat the skillet with oil. When oil begins to simmer place beef into the pan and quickly brown it on all sides, about 3-4 minutes total. Remove beef from pan and set aside to cool.

Carefully unfold the puff pastry sheet on a lightly floured large working surface. Gently roll out the puff pastry to about 12 x 12 inches flipping it over once while rolling.

Generously spread mascarpone cheese all over one side of the puff pastry sheet. Lay prosciutto slices across the puff pastry to cover the entire sheet. Place beef tenderloin in the center. Fold one side of the pastry over the tenderloin, then fold over the other. Fold over the ends and trim if necessary.

Combine the egg and water in a small bowl and beat to combine. Brush the top of the pastry with the egg wash. Place the beef on a lightly oiled baking sheet, seam side down and brush the top side with egg wash. (Egg wash should coat the pastry entirely). Carefully make 4-5 slits across the top of the pastry using the tip of a paring knife.

Bake in the preheated oven for 20-25 minutes until pastry is golden brown and a thermometer stuck into the center of the meat reaches 125 F for medium rare. Remove from oven and let it rest, about 10 minutes.

While tenderloin is baking prepare the Port Wine Chocolate Reduction Sauce: Melt butter in a sauce pan over medium-high heat. Add shallots, mushrooms and a pinch of thyme and sauté until veggies are softened, about 3-4 minutes. Stir in beef stock and port wine and bring to a boil until reduced to a little less than half, about 15-20 minutes. Reduce heat and whisk in chocolate. Season with freshly ground sea salt and black pepper and simmer until sauce thickens. Remove from heat and set aside.

Cut beef into large slices and serve with sauce.