Chateaubriand steak (also chateaubriand) is a meat dish cooked with a thick cut from the tenderloin filet. In contemporary times, chateaubriand cuts of beef refer to "a large steak cut from the thickest part of a fillet of beef". In the gastronomy of the 19th century, the steak for chateaubriand was cut from the sirloin, and the dish was served with a reduced sauce named chateaubriand sauce (or a similar sauce) that is 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.