Italian beef Wellington with prosciutto, mushroom duxelles, and flaky pastry is pure luxury. This high protein mediterranean dish is perfect for carnivore family celebrations.
Pat the beef tenderloin dry, rub with salt and black pepper, then sear in a hot pan with 1 tbsp olive oil for 2 minutes on each side to develop a deep golden crust. Remove and cool completely.
In a skillet on medium heat, add remaining olive oil, garlic, cremini mushrooms, and fresh thyme. Sauté until the mushrooms release moisture and become dry, about 10 minutes.
Lay out a sheet of puff pastry. Layer prosciutto slices slightly overlapping on the pastry, then spread the mushroom duxelles evenly over the prosciutto.
Place the cooled beef atop the duxelles, wrap tightly with prosciutto and pastry. Seal edges firmly and place seam-side down on a parchment-lined baking sheet.
Brush the pastry with beaten egg, chill for 20 minutes, then bake at 425°F (220°C) for 35–40 minutes until the pastry is golden brown and the beef reaches medium rare (130°F/54°C in center). Rest 10 minutes before slicing.