Complex sentence: Isigny sauce is found in recipe books from the 19th century however, according to Claire S. Cabot in the book; "A Short History of Ingredients" began to be called Hollandaise after WWII, when egg shortages forced imports from Holland.
Split into simpler sentences: Isigny sauce is found in recipe books from the 19th century. According to Claire S. Cabot in the book; "A Short History of Ingredients" began to be called Hollandaise after WWII, when egg shortages forced imports from Holland.