If she's talking about a Japanese restaurant, then she's likely talking about an Omakase menu, which is a tasting menu that the chef picks out for you, usually on the spur of the moment. Often in Japanese restaurants you sit at the bar, and get to interact with the chef as he's preparing your courses, he'll send you little bites of food as he makes them. It's my favourite way to eat in restaurants in general, you get to try alot of interesting stuff that the chef might not otherwise serve, and often foods that never find their way onto a printed menu.
Although I've worked mostly in French restaurants (although I have worked with several very skilled Japanese cooks), we did similar meals for some valued customers. Many of these menus got downright silly, my old boss (this is after I left the restaurant, still keep in touch) served a whole lobe of roasted foie gras with whole black truffles and porcinis as a course as part of a chef's tasting menu... Another restaurant I worked at did a 12 course menu, with fresh white Alba truffles on every course (we used several thousand dollars worth of truffles on a table of 12). Caviar, matsutake mushrooms, sea urchin, game and many other delicacies would find their way onto a chef's tasting menu - often they were too expensive or the supply too limited to put on the printed menu.
http://en.wikipedia.org/wiki/Omakase
Everything depends on the restaurant and chef you're visiting. For some it's an excuse to blow out product, or to draw business, for others it's a chance for the chef to personally serve you, to serve customers stuff he's not able to normally, and to be generous.