Ideally, you use the beef tenderloin, but that's gotten a little pricey. I've down-graded to using nice thick sirloin. I do hit it with a little tenderizer to level the playing field. And I've streamlined the process, making the mushroom mixture and sauce ahead and freezing them, cutting the last minute work to a minimum. You can adjust the size to fit your family, but I've never made one too big.
You'll need one package of puff pastry sheets or a whole bunch of crescent rolls, about three pounds of tenderloin or sirloin, butter, two tablespoons of flour, one package of mushrooms, one small onion, one clove garlic, a few slices of cooked deli ham, one egg or egg beaters, salt, pepper, tenderizer, cooking oil, 2/3 cup of red wine, 1 2/3 cup of beef bullion, and a splash of sherry.
Mince the mushrooms and cook in three tablespoons of butter, stirring until nearly dry. Add crushed garlic clove, diced onion and ham to mixture. Cook a few minutes more and set aside in refrigerator.
Bring red wine and beef bullion to a boil until liquid is reduced to half.
In a separate pan melt two tablespoons of butter and whisk in flour. Gradually whisk in reduced wine mixture, cook until sauce thickens and add sherry and one tablespoon of butter before serving. If you're making it ahead freeze or refrigerate before it gets thick. You can thicken it later.
Meat and crust…
Quickly sear the meat in small amount of oil and refrigerate until cool. Roll out the pastry sheets. Place on floured wax paper or foil. Spread enough mushroom mixture to cover the meat. Place the meat on top of the mixture and wrap the pastry around it sealing seams with water. I use the wax paper to support the crust as I wrap it. Place on cookie sheet. Use a fork to poke several vent holes in the crust.
You can either refrigerate this or cook it immediately. Brush crust with egg before baking.
You know your own oven better than I do, but I usually preheat my oven to 500 degrees and turn it down to 375 or 400 as soon as I put in the roast. I usually bake it for 25 minutes, hoping for medium rare. You can adjust accordingly or make smaller ones to get varying degrees of doneness, but they'll bake faster. You can also make individual
Remove from oven, let stand for ten minutes and slice with an electric knife.
In a variation of this recipe, I use turkey breasts or chicken instead of beef. I add spinach to the mushroom mixture when I do that, but everything else stays the same.