This seems to be one of those dishes that some people go in fear and trembling of, but it is not difficult.
Please note that the menu that follows is not replete with minute details – we don’t know what oven you use so things like temperatures we leave to you to adjust to suit your personal circumstances.
First find a good butcher (which can be hard these days) and purchase well-hung meat … that means a piece of beef that is nice and dark and not one of those pink things the supermarkets stock. When we did this over the new year our butcher provided a nice 3lb hunk of fillet that was way too big but included the filet mignon which we happily dissected out and are saving for another day and another meal. Anyway – get yourself a nice piece of fillet.
Sauté some mushrooms (oyster, shiitake, porcini etc – flavorsome varieties) with oil, butter, onions and herbs. Chop everything finely – a robo-chef will do the job for example.
Roll out flaky pastry … Home made or purchased. Paste it with the mushroom mixture, plonk your piece of beef in the middle, cover with the pastry and seal the edges.
Put it all in a baking tin and cook until done – depends on the size of your meat but less is better than more, you want some pink in there, don’t cook it to death.
Make a good rich, stock-based and reduced gravy sauce (adding some sherry or marsala wine is recommended).
Slice, eat , enjoy. Sugar peas, carrots, fingerling potatoes go well with this.