The Washington Post says "Cooking is not considered inventing; rather, it evolves. Copyright law specifies that "substantial literary expression in the form of an explanation or directions," such as a cookbook, can be copyrighted but that a mere list of ingredients cannot receive that protection." (Read more here. I also know that I have seen a cookbook by Julie Russo (of Silver Palate fame) and a cookbook by Michele Urvater with identical text. Urvater’s was first. Both were lists of ingredients you could use to give foods an ethnic flavor. Both were lengthy, detailed lists, and matched other detail for detail
Read more about the flap here.