Complex sentence: Isigny sauce is found in recipe books from the 19th century however, the story that the sauce began to be called Hollandaise after WWI, when butter shortages forced imports from Holland, is clearly inaccurate.
Split into simpler sentences: Isigny sauce is found in recipe books from the 19th century. However, the story that the sauce began to be called Hollandaise after WWI, when butter shortages forced imports from Holland, is clearly inaccurate.