Step 1

Season tenderloin evenly with 2-teaspoons salt and 1-teaspoon pepper. Vacuum seal and sous vide roast at the desired degree of doneness for two hours (130°F for medium rare).

Step 2

While tenderloin cooks, prepare mushroom duxelles. Working in batches, pulse mushrooms in a food processor until they are coarsely chopped, but not pureed; transfer to a plate. Pulse shallots and garlic in processor until minced.

Step 3

Preheat 1-tablespoon canola oil in a large non-stick pan over medium heat. Add shallot-garlic blend and sauté for 2 minutes. Stir in mushrooms, 1-teaspoon salt and 1/2-teaspoon pepper and continue to sear over medium heat until the mixture has released most of its moisture and becomes fairly dry, about 10 minutes. When pressed against the side of the pan, no juices should run from the mushroom mixture.

Step 4

Stir in thyme leaves and deglaze with alcohol, continually stirring for 2 minutes. Spoon duxelles onto a plate or sheet pan in a thin layer; refrigerate until cold (30 minutes to 1 hour).

Step 5

Remove tenderloin from bag and pat dry. Preheat a medium cast iron or stainless-steel skillet to high, add 1-tablespoon canola oil and sear tenderloin quickly on all sides. The goal here is to evenly brown the surface without cooking the inside. Make sure to sear both ends of the roast as well. This should only take a few minutes.

Step 6

Place tenderloin on a plate and refrigerate until cold, around 2 hours. Meanwhile, thaw puff pastry in refrigerator (if frozen).

Step 7

Lay out two 18-inch lengths of plastic wrap horizontally, slightly overlapping to create a sheet about 16-inches wide and 18-inches long. In the middle of the plastic, lay slices of prosciutto slightly overlapping them with the length of the prosciutto running from top to bottom. Ensure that the total prosciutto sheet created is the same width as the length of the tenderloin roast.

Step 8

Evenly spread a 1/4-inch layer of chilled mushroom duxelles on the entire prosciutto layer (there may be a small amount of duxelles left over depending on the size of the roast). Brush chilled tenderloin with Dijon mustard.

Step 9

Place tenderloin at the bottom edge of the duxelles topped prosciutto, roll towards the top using the plastic wrap to keep it adhered tightly to the roast. Once tenderloin has been wrapped, make sure no plastic has become tucked into the roll then tightly wrap in the plastic. Twist ends to ensure beef is tightly encased, it should feel like one cohesive piece; refrigerate 30 minutes to 1 hour until firm.

Step 10

Dust a workspace with a handful of flour, roll out one sheet of puff pastry until it is large enough to wrap the roast, the plastic wrapped roast can be used to estimate the sizing. Overlap two more 18-inch lengths of plastic (as with prosciutto) to create a large plastic sheet.

Step 11

Lay pastry in the middle of the plastic with the length running from top to bottom. Unwrap roast carefully, lay at the bottom edge of pastry. Wrap the roast in pastry, using the plastic to keep it tightly adhered to the roast. Brush top edge with about 1-inch of egg wash before completing the wrap. Once fully encased in pastry, tightly wrap the roast in the plastic wrap and refrigerate at least 10 minutes or up to 1 day ahead.

Step 12

Preheat oven to 425°F. Dust work space with another handful of flour, slightly roll out remaining pastry sheet. Dust sheet after rolling and use lattice cutter to firmly cut marks in sheet by working from bottom to top of the sheet. Gently spread lattice apart, using a paring knife to separate any pieces not completely cut through.

Step 13

Unwrap Wellington and place it on a sheet pan lined with silicone mat or parchment paper. Brush with egg wash and gently lay lattice over top of roast using a paring knife to adjust any lattice openings. Cut away excess lattice with bench scraper or paring knife and brush roast’s lattice with remaining egg wash.

Step 14

Bake Wellington 25 minutes, rotate roast 180 degrees and bake 20 more minutes until crust is golden brown with an internal temperature is 90° F.

Step 15

Remove from oven and let rest 10 minutes or until it reaches the internal temperature of desired doneness (130° for medium rare). Roast will continue to cook while resting so make sure to monitor internal temp so that it doesn’t exceed desired doneness.

Step 16

Slice with serrated knife into 1 to 1 1/2-inch thick slices to serve.