Instructions

1. Preheat the oven to 400°F and line a baking sheet with parchment paper.
2. Season the beef fillet generously with salt and pepper on all sides.
3. In a skillet over high heat, add the olive oil. Once hot, sear the beef fillet on all sides until browned. Remove from the skillet and let cool.
4. In the same skillet, add the chopped shallots, minced garlic, and finely chopped mushrooms. Season with thyme and cook until the mushrooms release their moisture and the mixture becomes dry. Remove from heat and let cool.
5. Spread the Dijon mustard evenly over the cooled beef fillet.
6. Roll out the puff pastry sheet on a lightly floured surface. Spread the cooled mushroom mixture evenly in the center of the pastry sheet.
7. Place the mustard-coated beef fillet on top of the mushroom mixture.
8. Wrap the puff pastry around the beef, ensuring the edges are sealed tightly.
9. Brush the beaten egg over the puff pastry to give it a golden finish.
10. Transfer the beef Wellington to the prepared baking sheet and bake for 25-30 minutes, or until the pastry is golden brown and the beef is cooked to your desired doneness.
11. Remove from the oven and let it rest for at least 10 minutes before slicing. This allows the juices to redistribute throughout the beef, ensuring a moist and flavorful result.
12. Serve the beef Wellington sliced to showcase the beautiful layers, and enjoy!