According to CMoS, which is technically correct? 1) a ham and cheese omelet 2) a ham-and-cheese omelet
It's a phrasal adjective, i.e., a compound modifier. CMoS 17 (5.92(i)) "Generally, if placed before a noun, the phrase should be hyphenated to avoid misdirecting the reader . . . compare small animal hospital with small-animal hospital." So you're avoiding "a ham" and "cheese omelet" (two separate things). You'll need the hyphens. CMoS then lists some exceptions but they mainly have to do with -ly adjectives and other things that don't apply here. I do see online that there's some talk about phrases that are assumed obvious and might be okay without the hyphens. Maybe you can get away with it that way? CMoS doesn't spell out your example specifically, but I'm thinking that might apply here. Just look at recipe books. They seem to forego the hyphens, and you know they're style checked. Sorry, I thought I had a definitive answer. It bothers me CMoS doesn't have a specific section on this. But after seeing nobody hyphenating, now I wouldn't either.
Thank you for the reply. That's precisely the problem; "a ham-and-cheese omelet" might be an unwarranted overkill. Still, I believe it is technically correct (even even very few people opt for it).
Sometimes you gotta opt for what's visually appealing over what's technically correct. The hyphens are atrocious.
Agreed. They're correct but they don't look good and I would personally leave them out. I don't think anyone reading it would think twice about it.
Technical correctness and visual appeal, both have their own places. Which I would opt for would depend on the material I am copyediting.
I've thought about this a bit, and I think I see the Chicago Manual loophole. CMoS starts their guideline with "generally," and they say to use hyphens for clarity. (You're connecting the adjective.) But if the phrase is so common that it naturally holds as a unit, then you shouldn't waste time with hyphens. That's why all the cookbooks ignore them. Most of the time (generally), the hyphens appear, but when there's no need to disambiguate, they don't.
Wouldn't it be more correct to write "a ham and a cheese omelet" for two separate things making the hyphen in "a ham and cheese omelet" unnecessary? all this ham and cheese talk made me hungry! I want the omelet in a sandwich!
I believe it is the same as ham-and-cheese croissant. However, stylistically, I would always go with "a ham and cheese omelette / croissant".
