Individual Beef Wellington with Mushroom Duxelles

Season the beef filets generously with salt and pepper. In a very hot pan with a splash of oil, sear the meat for 60-90 seconds per side until browned but raw in the middle. Remove from the pan and immediately brush all over with English mustard. Set aside to cool.

To make the duxelles, finely chop mushrooms in a food processor until they resemble coarse breadcrumbs. Sauté in a large dry pan over medium-high heat with shallots, garlic, and thyme. Cook until all the moisture released by the mushrooms has completely evaporated—the mixture should be thick and paste-like. Season with salt and pepper, then cool completely.

Lay out a sheet of plastic wrap. Arrange 2 slices of prosciutto in the center, slightly overlapping. Spread a thin layer of the cooled mushroom duxelles over the prosciutto. Place a beef filet in the center and, using the plastic wrap, roll the prosciutto and mushroom mixture tightly around the beef. Tie the ends of the plastic wrap to form a tight log and refrigerate for 30 minutes.

Preheat your oven to 400°F (200°C). Roll out the puff pastry and cut into 4 squares large enough to wrap each filet. Remove the beef from the plastic wrap and place in the center of a pastry square. Brush the edges with egg yolk and fold the pastry over the beef, sealing tightly and trimming any excess.

Place the parcels seam-side down on a baking sheet lined with parchment paper. Brush the tops with egg yolk and use the back of a knife to lightly score a decorative pattern into the pastry. Chill for another 10 minutes.

Bake for 20-25 minutes until the pastry is deep golden brown and the internal temperature of the beef reaches 125°F (52°C) for medium-rare.

Remove from the oven and let rest for 10 minutes before serving to ensure the juices stay within the meat.