Use butchers twine to tie the bison tenderloin tightly into 6-8 sections. This will help the tenderloin hold its shape.

In a cast iron skillet on high, heat the olive oil until smoking then sear the bison tenderloin on all sides including the ends for 2-3 minutes per side, until browned evenly.

Remove the bison tenderloin from the skillet and set aside. Brush heavily with Dijon mustard. Let cool while preparing the duxelles, about 20-30 minutes. Cut and discard the twine.

Meanwhile, in the still hot skillet, deglaze the bottom with a splash of sherry. Scrape up the browned bits as the liquid evaporates.

Prepare the duxelles. When most of the liquid is gone, add the chopped pancetta. Cook until most of the fat has melted off and the meat is starting to get crispy.

Stir in the shallot followed by all of the minced mushrooms. Reduce the heat to medium and continue cooking until the mushrooms have released most of their moisture, about 20-30 minutes. When sufficiently browned, remove from the heat and cool for 15 minutes.

Place a long sheet of plastic wrap on a clean working surface. The plastic wrap should be long enough to be able to wrap all the way around the tenderloin.

Lay out the slices of prosciutto on the plastic wrap so that they are slightly overlapping. There should be enough slices to cover and wrap around the entire tenderloin.

Spread the duxelles in an even layer from edge to edge of the prosciutto. Sprinkle on the fresh thyme. Place the tenderloin on the long side of the laid out prosciutto and duxelles. Use the plastic wrap to wrap the tenderloin completely and tightly. Rest 20 minutes.

Set out the puff pastry sheet to begin thawing, about 15-20 minutes. When mostly thawed, dust a clean surface with a tablespoon of flour and roll out the pastry so that it is large enough to wrap around the entire tenderloin.

Preheat the oven to 375°F. Grease a baking sheet with cooking spray or parchment paper. Transfer the puff pastry to the baking sheet. (TIP: It will be mush easier to roll up the tenderloin on the baking sheet so you don’t have to move it and risk it opening up.)

Unwrap the tenderloin from the plastic and place it on the long end of the puff pastry. Roll the wrapped tenderloin in the pastry and then tuck the ends tightly under so that the meat is completely encased in pastry.

Brush lightly with egg wash and use a sharp knife to lightly score the top of the wellington in a crisscross pattern.

Bake the bison wellington for 30-40 minutes or until a thermometer inserted in the center reads 120°F. Remove the wellington from the oven. The bison’s internal temperature will continue to rise. Let it rest until the internal temperature reaches 150°F, about 15-20 minutes. Do not cut the wellington at this stage.

While the wellington is resting, heat a sauce pan over medium high heat. Melt the butter until foaming then whisk in the Dijon mustard, honey and vermouth. Bring to a rolling bubble then simmer for 15 minutes or until thickened. Remove from the heat and cool 10 minutes.

Slice the bison wellington into individual slices and serve with a side of honey mustard vermouth sauce. Enjoy!