Ingredients:

  • 1.5 lb (680 g) Beef Tenderloin (Centre-cut fillet), trimmed
  • 2 Tbsp (30 ml) Dijon Mustard
  • 1 Tbsp (15 ml) Olive Oil
  • 1 Tbsp (14 g) Unsalted Butter (for searing)
  • Salt and Black Pepper, to taste
  • 1 lb (450 g) Mixed Mushrooms (Cremini, Shiitake), cleaned and roughly chopped
  • 2 medium (100 g) Shallots, finely minced
  • 1 tsp (5 ml) Fresh Thyme Leaves
  • 2 Tbsp (30 ml) Dry Sherry or dry white wine
  • 1 Tbsp (14 g) Unsalted Butter (for duxelles)
  • 12 slices Prosciutto (approx. 100g), thinly sliced
  • 14 oz block (400 g) Puff Pastry, all-butter preferred, chilled
  • 2 large Egg Yolks, beaten with a splash of water (for egg wash)
  • Flour, as needed for dusting

Instructions:

  1. Sear the Beef: Pat the fillet very dry. Season aggressively with salt and pepper. Heat oil and butter in the pan until shimmering. Sear the fillet on all sides (including the ends) for 30–45 seconds per side to form a deep brown crust.
  2. Coat and Chill: Immediately remove the beef and brush liberally with Dijon mustard while it is still warm. Wrap tightly in plastic wrap and chill in the refrigerator for at least 30 minutes.
  3. Prepare the Duxelles: Pulse the mushrooms, shallots, and thyme in a food processor until finely minced (like coarse sand).
  4. Cook Down the Duxelles: Melt the butter in the same pan. Add the mushroom mixture and cook over medium heat, stirring frequently. Deglaze with sherry. Continue cooking until all the moisture has evaporated and the mixture is very dry (about 15–20 minutes). Spread the mixture onto a plate and chill completely.
  5. Create the Prosciutto Barrier: Lay a large sheet of plastic wrap on your work surface. Arrange the prosciutto slices in an overlapping layer large enough to fully encase the fillet.
  6. Layer the Duxelles: Spread the chilled duxelles evenly over the prosciutto layer.
  7. Wrap the Fillet: Remove the chilled beef from its wrap and place it at the edge of the prosciutto/duxelles layer. Use the plastic wrap to tightly roll the meat, creating a perfect, firm cylinder. Twist the ends of the plastic wrap to tighten the bundle.
  8. Initial Chill: Chill the wrapped cylinder for 1 hour. This ensures the log holds its shape before pastry application.
  9. Roll the Pastry: On a lightly floured surface, roll the puff pastry into a rectangle large enough to completely encase the beef log, about ⅛ inch (3 mm) thick.
  10. Final Assembly: Remove the beef log from the plastic wrap. Brush the edges of the pastry with egg wash. Place the beef onto the pastry and roll it up, ensuring a tight seal. Trim excess pastry. Seal the ends by folding them underneath.
  11. Decorate and Egg Wash: Score the pastry lightly (do not cut through to the meat). Brush generously with the egg wash.
  12. Final Chill: Place the prepared Wellington on a parchment-lined baking sheet and chill for a final 30 minutes. This prevents the pastry from shrinking drastically in the oven.
  13. Bake: Preheat oven to 400°F (200°C). Bake for 30–40 minutes, rotating halfway through.
  14. Monitor Temperature (The Key Management Point): Insert a digital thermometer into the centre of the meat. Cook until the internal temperature reads 125°F (52°C) for Medium-Rare.
  15. Crucial Rest: Remove from oven. Rest the Wellington for 10–15 minutes before slicing. This allows the juices to redistribute.