I tried every which way from Sunday to screw this dish up. I let the meat thaw too long, wrapped it halfway and let it sit for a day, took little care in the actual cooking, and then added insult to injury by not eating it for a day after.
And it was still damn delicious, despite the disrespect.
healthy-ish

(Nearly) Weeknight Wellington
3-ish pound beef tenderloin
Package filo or puff pastry dough
250g mixed mushrooms
2 tsp beef stock starter
1/2 tsp dry thyme
1 tsp soy sauce
Bourbon
Olive oil
Salt & pepper
1 package proscuitto
Chinese hot mustard
1 egg
Preheat your oven to 400F/200C.
Rub your tenderloin with oil, salt & pepper generously. Put on a roasting pan and bake 10 minutes to brown a bit.
While the beef is working, chop the mushrooms very fine.
Sauté in 1 Tbsp olive oil until softened. Add 2 tsp beef stock starter, 1/2 tsp dried thyme, 1 tsp soy sauce, a splash of bourbon and 1/3 cup water. Let cook, stirring often, until the liquid is absorbed.
When the beef is finished, remove and let cool completely.
Remove the mushrooms from the heat and let cool as well.
Lay some Saran Wrap down (or a layer of aluminum foil + a layer of baking paper if you, like me, didn’t get your ish together). Layer the prosciutto over top in a single layer with no gaps showing.
Spread the mushrooms over top in a thinish layer to almost the edges.
Slater the top of the beef generously with the mustard and lay down over the mushrooms mustard side down.
Roll the ham around the beef, using the wrapping to do so, tightly. Chill at least :30 (I let mine go overnight and it was fine).
When you’re ready to cook, preheat the oven again to 400F/200C.
Prepare a baking sheet. Roll the dough over the sheet into a flat rectangle.
Unwrap the beef roll and place onto the edge of the dough. Wrap the beef in the dough, ending up seam side down.
Brush the seam with the egg (beaten) to seal. Tuck the ends under as well to make a package.
Make some small slashes in the top to let steam escape. Brush with beaten egg.
Bake :30 for rare-mid rare; longer for more doneness.
Serves 4? 5? 6? You decide how far you want to stretch it