If you heard me say it aloud you'd probably say that I was saying "corn beef," although I understand it to be and write it "corned beef."In the Cambridge Dictionary I can only find "corned beef," and indeed I have only ever heard of corned beef! Merriam-Webster, on the other hand, contains corn beef. I believe that the latter is used in America, whereas in England people say corned beef. In all the British writers I have ever read, corned beef was always used--never corn beef.