You're welcome pjms9, and thanks for the extra information.
Since you are making such a long book, your choice of software will be very important. From what you have said I can make a number of inferences:
Your layout will be simple
Cookbooks, usually, keep to a simple format so that the cook can easily see what ingredients they need and what they need to do with them. Your layout, as described, seems to be fairly standard for this kind of thing. Either Scribus or O/LO can handle simple layouts so there is not much to base a decision on there.
You will have multiple contributors
This will probably mean that various people will be creating different parts of the book and then these parts will need to come together at some point. Both Scribus and O/LO allow you to combine documents so either would allow you to work that way but...
Scribus is difficult to learn, or, at least, more difficult to learn than a word processor. Assuming that not all of your contributors will have the time and/or patience to learn Scribus I would say that the initial creation of the recipes should be made in O/LO. (Each recipe could be in its own document, or you could group recipes together by author, that would be entirely your decision.) If the recipes are being created in O/LO then it would make sense to gather them all together in O/LO. There's no reason to add any additional complication if it's not needed.
O/LO also has commenting and collaboration tools that Scribus lacks.
You have complicated referencing requirements
With cookbooks it is useful to have multiple TOCs. For instance, you may have a list of recipes for meat dishes, and another for vegetarian dishes, or others listing dishes from different regions. You could also want to have multiple indexes which will answer reader's questions such as "I like that dish that used veal, where can I find it?".
Because Scribus cannot handle such things automatically it would be extremely laborious to attempt it manually. For example, what if you added a new recipe in the middle? Every reference to something after the added recipe would have to be manually altered. Not a good situation. Keeping it all within O/LO - which can handle this sort of thing without breaking a sweat - seems to be the way to go.
So, all in all, I would say that your decision go with O/LO is the right thing to do. I'm not saying that Scribus wouldn't be able to do what you want, it's just that it would add way too much extra work and complication. It's simply not built for this kind of thing.
It might sound odd for someone in a Scribus forum recommending the use of another application but I would be far happier telling you to use something else than hearing about you getting frustrated trying to use the wrong tool for the job.
I'm afraid that my experience of ePublishing stops at knowing that some publishers have specific PDF requirements and that eBooks require a different - fluid - format as compared to the static PDF format. I've never published anything for an eBook and hardly any of my work gets printed so I can't help on those issues. I only mentioned it so that you didn't go too far down one road only to find that you had taken the wrong path.
Since it sounds like you will probably be using O/LO it might be worth asking the questions in the forums relevant to that particular software. You might be able to get some answers from this forum - I know that many people have asked similar questions in the past - but the answers in this forum are more Scribus-oriented and, because of that, they may mislead you as to what is best for how you proceed with O/LO.
Having said that, there are some people in this forum who have had a lot of experience with publishing in general and they could give you some very useful advice. You could ask similar questions in multiple forums and see what sort of answers you get.
Anyway, good luck with your book. When you get it out to the world you might want to come back and add a link here to show people what's possible. It's always good to hear from people who have used open source software to create things, no matter which application they have used. There's no competition between Scribus and O/LO, they're just different ways of doing similar things.