Demi-glace warm. At this point, the espagnole is prepared, and when it is finished, the brown stock is added in equal portions to the espagnole. Demi-glace keeps very well, about six months refrigerated or almost indefinitely frozen. Due to the considerable effort involved in making the traditional demi-glace, chefs commonly substitute a simple "jus lié" of veal stock or to create a simulated version, which the American cookbook author Julia Child referred to as a "semi-demi-glace"(i.e. sans espagnole sauce). However, even today, many chefs who prepare French "haute cuisine" use a demi-glace prepared in their own kitchen. Concentrates and mixes, mostly
French cuisine and created new combinations and pairings. Some have speculated that a contributor to nouvelle cuisine was World War II when animal protein was in short supply during the German occupation. By the mid-1980s food writers stated that the style of cuisine had reached exhaustion and many chefs began returning to the haute cuisine style of cooking, although much of the lighter presentations and new techniques remained. There are many dishes that are considered part of French national cuisine today. A meal often consists of three courses, "hors d'œuvre" or "entrée" (introductory course, sometimes soup), "plat principal" (main course), "fromage" (cheese