"The Surprising Origin of the Filet-O-Fish: A Lenten Tradition's Influence"

McDonald's franchisee Lou Groen created the Filet-O-Fish sandwich in 1962 to attract Catholic customers abstaining from meat on Fridays during Lent, leading to a quarter of its sales occurring during the 40 days of Lent. The sandwich, made of Alaskan pollock, remains popular year-round and is a testament to Groen's customer-first approach, outshining McDonald's founder Ray Kroc's alternative meatless idea, the Hula Burger.