3 lbs beef tenderloin, trimmed of fat
2 tbsp high quality Dijon mustard, if possible
1 sheet of thawed puff pastry (making your own is very, very rarely worth the effort)
6 slices of prosciutto
8 oz crimini mushrooms
1 large shallot, diced
3 cloves of garlic, minced
1 tbsp unsalted butter
1 large egg, beaten
2 tbsp milk, for the egg wash
Kosher salt and freshly cracked black pepper to taste
1Heat your water bath to 124 degrees Fahrenheit, or 51 degrees Celsius.
2Season your beef tenderloin extremely liberally with kosher salt and freshly cracked black pepper. Make sure to work the seasoning deeply into the folds of the meat.
3Place you beef tenderloin in a large, vacuum sealable bag.
4Cook in the water bath for 2 hours.
525 minutes before the cook is done finely dice your mushrooms, garlic, and shallots. Process until roughly the same size - almost a course paste - this is sometimes known as duxelles.
6Heat a pan to medium and cook the mushroom-mixture for 5-10 minutes. You can lightly salt the mushrooms to encourage them to give up more of their moisture if desired. Set the mixture aside.
7Re-grease and re-heat your pan with another 1 tbsp of oil. Sear the beef on all sides until browned - 30 seconds per side.
8Remove from the pan and rub the beef tenderloin down with the dijon mustard.
9Next, lay out a large section of plastic wrap. Layer the prosciutto, mushroom mixture, and beef tenderloin in that order.
10Slowly and carefully, begin to roll up the beef tenderloin until the log is completely wrapped in the prosciutto. Tie off the ends of the plastic wrap and place in the freezer for 20-minutes to firm up. This is also a good time to set your oven to pre-heat to 475 degrees for finishing.
115 minutes before the tenderloin is done in the freeze roll out your puff pastry until smooth. Brush with a light egg wash by combining 2 tbsp of milk with 1 beaten egg.
12Unwrap your beef tenderloin from the plastic wrap, place on puff pastry, and wrap carefully. Using your sharpest kitchen knife slice off any excess puff pastry to tidy the ends,
13Place the beef wellington on a rimmed baking sheet lined with parchment paper.
14Bake at 575 degrees for 10 minutes until the pastry is golden brown. If you would prefer a clear glaze you can substitute water for milk in the egg wash.
15Finally, slice you beef wellington and enjoy with some British favorite like Yorkshire Pudding.
16Photo credit: istetiana/Shutterstock