Chateaubriand sauce

Chateaubriand is a dish that traditionally consists of a large front cut fillet of tenderloin grilled between two lesser pieces of meat that are discarded after cooking. While the term originally referred to the preparation of the dish, Auguste Escoffier named the specific front cut of the tenderloin the Chateaubriand. In gastronomy of the 19th century, the steak for Chateaubriand could be cut from the sirloin, and served with a reduced sauce named Chateaubriand sauce or a similar, that was prepared with white wine and shallots moistened with demi-glace, and mixed with butter, tarragon, and lemon juice. It was also traditionally served with mushrooms. A common practice in naming dishes is to name them after an individual. For example, the sandwich — two slices of bread with something between — was named after John Montagu, 4th Earl of Sandwich. Similar examples include carpaccio named after the Italian painter Vittore Carpaccio, and Chateaubriand named after the French author François-René de Chateaubriand. The dish has retained its capitalization while the other examples no longer retain their surname origins.

Source: Wikipedia