Tournedos aux Champignons

Tournedos aux champignons (beef tenderloin medallions with mushrooms) teaches the quickest and most exacting family of pan sauces: the fond beneath the beef must be deeply brown, never black. Before you touch the pan, dry the tournedos thoroughly. Moisture prevents a crust, and without that crust the sauce has nothing to say.

The original entry assumes a saucier on staff, mushroom cooking liquor waiting, a rich brown stock never off the fire, and brigade portions ready to arrange in a crown. Here, four tournedos share one skillet. You make the mushroom liquor yourself, reduce a small measure of stock into the required mushroom sauce, then use the beef pan to unite them. The separate sauce station is brigade scaffolding and can go. Butter-frying the beef, draining the excess fat, deglazing with mushroom liquor, and pouring the mushrooms into the crown are the dish, so every one of those steps stays. One cook, one stove, one evening.

Expect a deep bronze crust, tender rosy beef, and mushrooms gathered in a glossy brown sauce at the center of the platter. Keep your eye on the butter as the tournedos cook. Hazelnut brown gives character; black gives bitterness. That browning is the step that decides everything.