Classic beef Wellington with dry-aged Chateaubriand

Salt the Chateaubriand all over with kosher salt, wrap in plastic on a quarter sheet and dry brine in the fridge at least two days.

Towel the beef thoroughly dry, so there is zero moisture on the outside, and sear it refrigerator cold in about a quarter cup of smoking vegetable oil over super high heat. The goal is colour only, no cooking.

Cool the seared beef a few minutes and return it to the fridge; it must be refrigerator cold when it goes into the Wellington.

Rinse a pound of cremini mushrooms and chop off the tough woody ends.

Chop the mushrooms and two minced shallots in a food processor, pulsing so they circulate.

Saute the mushroom and shallot mixture in four tablespoons of butter in the same cast iron pan, salting lightly to draw out moisture.

Cook until all the water has cooked out and the mushrooms begin to brown.

Add a teaspoon of chopped thyme and a quarter teaspoon of chopped rosemary as they start to dry out.

Kill the heat, add the cognac and light it to deglaze the pan.

Add half a cup of heavy cream to thicken and tighten the pate, and a little salt.

Spread the duxelles out to cool completely under a sheet of parchment; nothing warm goes into the pastry.

Roll the thawed puff pastry at least four inches wider than the Wellington and return it to the fridge.

Lay down a single sheet of filo, shingle slices of prosciutto over it and spread the duxelles on top.

Brush the beef thoroughly with Dijon mustard, set it on the duxelles and roll it up a little at a time, using the plastic wrap and the table to pull it super tight.

Refrigerate about 30 minutes.

Set the parcel on the puff pastry, brush the inside so there is less of a gap, snip off the excess, pull, stretch and pinch the seam closed and press the sides in like wrapping a gift, seam side down.

Wrap in plastic and refrigerate one hour.

Press a lattice cutter through a sheet of pastry to cut the lattice.

Brush the chilled Wellington thoroughly with beaten egg, drape the lattice over, trim the errant ends and tuck the rest underneath.

Refrigerate about 20 minutes so the lattice sets.

Brush again with egg and finish with flaky salt.

Bake 25 to 45 minutes depending on size and thickness, keeping an eye on it and using a temp probe; Wellington is traditionally served medium rare.

Rest at least 15 minutes before cutting, then garnish with parsley.