Ingredients:

• 1 pound beef tenderloin
• Salt and pepper to taste
• 1 tablespoon olive oil
• 2 tablespoons Dijon mustard
• 8 oz mushrooms, finely chopped
• 2 cloves garlic, minced
• 1 tablespoon fresh thyme, chopped
• 2 tablespoons butter
• 1 sheet puff pastry, thawed
• 1 egg, beaten

Instructions:

1. Preheat oven to 425°F (220°C).
2. Season the beef tenderloin with salt and pepper.
3. Heat olive oil in a pan over high heat and sear the beef on all sides until browned, approximately 2 minutes per side. Remove and let it cool slightly.
4. Brush the beef with Dijon mustard.
5. In the same pan, add butter, mushrooms, garlic, and thyme. Sauté until mushrooms release their moisture and the mixture turns golden brown, about 5-7 minutes. Let it cool.
6. Roll out the puff pastry on a flat surface.
7. Spread the mushroom mixture over the center of the puff pastry.
8. Place the beef on top of the mushroom layer.
9. Wrap the puff pastry around the beef, sealing the edges carefully to enclose it completely.
10. Brush the entire pastry with beaten egg to ensure an even golden brown crust.
11. Place the wrapped beef on a baking tray seam-side down.
12. Bake in the preheated oven for 40 minutes until the pastry is golden brown and the internal temperature of the beef is to your liking (medium-rare is 135°F).
13. Remove from the oven and let it rest for 5 minutes before slicing.

Notes:

Feel free to add your favorite vegetables or protein to customize this dish.