" Fridays taught me the French philosophy of the leftover, codified (I later discovered) in my Institut Bocuse textbook and older books, such as the 1899 Art of Using Leftovers. There were rules—never store a leftover in a serving dish or a cooking vessel; never store a warm liquid in a closed container without cooling it first; never reuse a preparation made with raw egg; never keep anything for more than three days; and, the most important of all: Never, under any circumstances, use a leftover twice. A leftover has one chance: to be made even better than the original. "

― Bill Buford , Dirt: Adventures, with Family, in the Kitchens of Lyon, Looking for the Origins of French Cooking