Though we think of cooking as art, that does not make a recipe copyrightable.
"A mere listing of ingredients is not protected under copyright law. However, where a recipe or formula is accompanied by substantial literary expression in the form of an explanation or directions, or when there is a collection of recipes as in a cookbook, there may be a basis for copyright protection." — The Copyright Office of the US Government
"A list of ingredients cannot be copyrighted. An idea, concept, system or method of doing something cannot be copyrighted either. Only the substantially literary expression associated with a recipe can be copyrighted. To the extent there are only so many ways to say "boil water" it is not creative, or therefore protected as copyright. However, If the recipe directions or description are a wholesale copy of another person's creative literary expression, they are in violation of copyright. So even if the recipe originated elsewhere, even if the ingredients are still the same, if the directions and descriptions of your posted recipe are "(essentially) "in your own words, it is your recipe."
(Thanks to the Recipe Zarr website for this great information)