) cooked with foie gras
in a puff pastry
Season a tenderloin with salt and pepper and sear it in a hot pan, then cook in a 400 degree oven for 20 minutes. Let the tenderloin rest and reserve the pan juices (strain off the fat, though).
While the tenderloin cooks, sauté half a pound of sliced mushrooms in a bit of butter. When the mushrooms start becoming dry (most of the moisture is cooked off), add 1/4 cup of port or madeira and reduce again. Let the mushrooms cool.
Take some puff pastry crust (large enough to wrap around the tenderloin with room to spare) and spread thinly and evenly with paté de foie gras. Spread the mushroom mixture on top. Place the tenderloin on top and roll it up. Chill it for 1-2 hours (this makes the puff pastry come out flaky). Cook in a 400 degree oven for 25-30 minutes (25 minutes will give a medium-rare to medium result, 30 will tend towards medium-well), reduce the heat to 350, brush the crust with a bit of butter, and cook for 5-10 minutes more (until the crust is good and brown).
While the wellington cooks, make a sauce by combining the pan juices from the first stage with 1/3 cup of madiera or port (a burgundy will also be great, but give a difference character to the sauce). Reduce the mixture to about 1/3 of the original volume. Add 1.5 teaspoons of arrowroot or corn starch dissolved in a couple of teaspoons of cold water, and stir the mixture while boiling until it reaches the desired consistency.
Allow the wellington to rest for 5 minutes after it comes out of the oven, then slice into inch-thick disks and serve with the sauce, and some sort of potato.
If you think foie gras is gross or unethical, omit it and use an extra quarter pound of mushrooms.