Grocery List:

• 1 – 4-pound center-cut beef tenderloin, trimmed (filet mignon cut)
• 3 – pints (1½ lbs) white button mushrooms
• 2 – shallots
• 4 – cloves of garlic
• 2 – sprigs of fresh thyme
• 2 – TBSPs unsalted butter
• 2 – TBSPs olive oil
• 2 – TBSPs Dijon Mustard
• 2 – large eggs
• 1 – handful of flour
• 1 – package of pastry puff or phyllo dough, thawed (2 sheets)
• Salt and Pepper to taste

Recipe:

1. Set out the beef tenderloin a couple of hours before beginning this recipe. Optionally, tie twine around it in 3-4 places to help maintain shape while cooking
2. Start a Duxelles by finely chopping the mushrooms, shallots, garlic, and thyme. Then, add them to a pan with butter and olive oil over medium heat. Sauté for about 10 minutes and season with salt and pepper to taste. Then, set aside to cool.
3. Drizzle olive oil over the beef and season it generously with salt and pepper. Sear it all over in a hot pan for about 2-3 minutes total, remove the twine ties, and set aside.
4. Lay down a long piece of parchment paper, about 18-24″. It will need to be able to wrap around the tenderloin.
5. Roll the pastry puff out on the parchment paper until it’s about ⅛ inch thick, adding flour to the surface as needed. Spread the Dijon mustard over most of the pastry puff dough, leaving 4-6 inches on one side for the Boursin cheese and a 1-2 inch border. Spread the Boursin cheese on the pastry puff, then spread the Duxelles mixture over the pastry puff. Create an egg yolk wash by separating the yolks (removing the whites) and adding a splash of water. Spread this over the border of the pastry puff. This will help everything stick together when we roll it. You may have extra egg wash; we will use this on top later.
6. Lay the tenderloin on the pastry puff, opposite side of the Boursin cheese, and begin rolling towards the Boursin. This will allow the cheese to be on top. As you’re rolling, tuck in the ends and ensure it remains rolled tightly. However, avoid pulling too tightly and ripping the dough. Remove the parchment paper, and cover the Wellington in Saran Wrap.
7. Set the Wellington in the fridge for 20-30 minutes before cooking to help it hold its shape.
8. Preheat oven to 425°F.
9. Remove the Saran Wrap and brush the top of the Wellington with the remaining egg wash. Optionally, cut any extra puff pastry dough into ½ inch strips and lay over the Wellington to create a lattice as shown below.
10. Cook in the oven until the internal temperature reaches 123°F (about 50 minutes), then remove from the oven and allow it to rest for 5-10 minutes before serving.
11. Slice into 1-inch slices and serve warm.

Notes:

• The layers of the Wellington are customizable, and many people like to add prosciutto.
• You’ll gain a lot of mass in the puff pastry while it’s in the oven, so it’s important to roll it out thinly.
• If making ahead, stop after step 7, and then be sure to remove it from the fridge a couple of hours before you plan to cook it. This will help prevent burning the crust before the inside cooks.