Ingredients:

  • 2 Tbsp Unsalted Butter
  • 2 Tbsp Olive Oil
  • 1 lb Cremini or Chestnut Mushrooms, finely chopped
  • 2 Shallots, finely diced
  • 2 cloves Garlic, minced
  • 2 Tbsp Dry Sherry or Madeira (optional)
  • 1 tsp Fresh Thyme, finely chopped
  • ½ tsp Sea Salt
  • ¼ tsp Freshly Ground Black Pepper
  • 1 lb Beef Tenderloin (Filet Mignon), trimmed and cut into 16 uniform 1-inch cubes
  • 1 Tbsp High-Heat Oil (e.g., grapeseed or canola)
  • ½ tsp Kosher Salt (for searing)
  • ¼ tsp Freshly Ground Black Pepper (for searing)
  • 2 Tbsp Dijon Mustard
  • 8 slices Prosciutto (thinly sliced), halved lengthwise (to make 16 strips)
  • 1 box All-Butter Puff Pastry, thawed but kept cold
  • 1 Large Egg (for egg wash)
  • 1 tsp Water (for egg wash)
  • Flour (for dusting)
  • Maldon Sea Salt Flakes (for finishing)

Instructions:

  1. Sauté Aromatics: Melt butter and oil in a pan over medium heat. Add shallots and garlic; cook until softened (3 minutes).
  2. Add Mushrooms: Add the finely chopped mushrooms, thyme, salt, and pepper. Turn the heat to high.
  3. Dry the Mixture (Crucial Step): Cook the mushroom mixture, stirring frequently, until all the liquid has evaporated and the mixture is very dry (about 12–15 minutes). Spread the duxelles onto a plate or tray to cool.
  4. Finish and Chill Duxelles: Deglaze the pan with sherry (if using) and cook for 1 minute. Chill the duxelles completely in the refrigerator (at least 20 minutes).
  5. Season Beef: Pat the 16 beef cubes dry and season heavily with salt and pepper.
  6. Sear Beef: Heat the high-heat oil in the frying pan until smoking hot. Sear the beef cubes quickly on all sides—about 30 seconds per side—to create a crust. The beef should remain raw in the centre.
  7. Chill Beef: Immediately transfer the seared beef to a plate and place it in the refrigerator until cool (about 15 minutes).
  8. Prepare Pastry: Lightly flour a work surface. Roll the puff pastry sheet slightly thinner (to about ⅛-inch / 3 mm thick). Using a 2.5-inch round cutter, cut 16 circles or squares.
  9. Mustard and Prosciutto Barrier: Brush the top of each chilled beef cube lightly with Dijon mustard. Lay a strip of prosciutto (halved lengthwise) on each pastry piece.
  10. Layer Assembly: Place a small spoonful (about 1 tsp) of chilled duxelles onto the prosciutto strip, followed by a seared beef cube.
  11. Wrap Tightly: Bring the edges of the pastry up and over the beef, pinching the seams firmly at the top to seal the entire parcel. Trim off excess pastry if necessary. Place seam-side down on a parchment-lined baking sheet.
  12. Egg Wash: Whisk the egg and water to make the egg wash. Brush the Wellington bites generously.
  13. Final Chill and Preheat: Chill the assembled bites for 15 minutes. This prevents butter melt. Preheat oven to 425°F (220°C).
  14. Bake and Serve: Place the baking sheet into the hot oven. After 5 minutes, reduce the oven temperature to 400°F (200°C). Bake for a further 13–15 minutes, until deeply golden brown and puffed. Sprinkle immediately with Maldon sea salt flakes, and let rest for 5 minutes before serving.