Easy Beef Wellington Recipe

Mushroom layer:

1. Start by making the mushroom layer. Place the 1.5 pound mixed mushrooms (chopped) and coarsely chopped 1 sweet or white onion in a food processor and pulse several times until finely chopped.
2. Heat the 2 tablespoons olive oil over medium-high heat in a large skillet and the mushroom-onion mixture, 3-4 garlic cloves (minced), and seasonings (1 teaspoon dried thyme, 1/2 teaspoon dried rosemary, and Kosher salt and pepper). Cook, stirring frequently, for 8-10 minutes until most of the liquid is absorbed. Continue to cook over medium heat, stirring often for 6-8 minutes, until the mushrooms brown and there's no liquid left. This step is important because having no liquid means crispy pastry at the end. Taste and adjust the salt to your taste.

Tenderloin:

1. To prepare the 2.5 pounds beef tenderloin, pat dry with a paper towel. Trim the excess fat, then tie with butcher's twine 4-5 times around the tenderloin to help keep its shape while cooking.
2. Season with Kosher salt and pepper on all sides.
3. Heat the 2 tablespoons olive oil in a large skillet and cook the tenderloin for 2 minutes per side (8 in total) until all sides are golden and seared. Remove from heat.
4. In a small bowl, combine the 2 tablespoons dijon mustard with 1 tablespoon sriracha sauce. Remove the butcher's tie and rub the seared tenderloin all over with this mixture.

To assemble the beef Wellington:

1. Roll a large piece of cling film on your clean working table.
2. Lay with the 12 thin slices prosciutto, slightly overlapping each other. You need to form a square as long as the tenderloin. Spread the mushroom mixture over the prosciutto.
3. Place the tenderloin on one end of your prosciutto square. Roll it tightly with the help of the cling film.
4. Refrigerate for 30 minutes.
5. Preheat the oven to 425°F.
6. Roll out the 14 ounces frozen puff pastry to create a rectangle 2 inches larger than the length of your prepared tenderloin.
7. Remove the tenderloin from the cling film and place it on one end of the pastry rectangle.
8. Roll tightly, tucking the ends in. You might want to cut and remove any excess pastry.
9. Place the prepared Wellington seam at the bottom of a sheet pan.
10. Brush with beaten 1 large egg and make a few light diagonal cuts on the top (don't go all the way through the pastry), 1 inch apart. Sprinkle with 2 teaspoon poppy seeds and flaky salt, if desired.
11. Bake for 35-40 minutes, or until the internal temperature reaches 125ºF (for rare).
12. Allow it to rest for 15 minutes before slicing.