I have no clue about fine dining, but I've learned every restaurant, and every chef or manager is different across all the other ones I have worked. You really may not know what you're getting into between restaurants. I imagine fine dining and hotels are more standard though.
I'm usually a linecook, and most of my bona fide prepcook jobs were 2nd part time jobs and have been pretty straight forward, with them expecting little except being able to cut veggies at a reasonable pace without hurting myself and being able to read recipes and follow simple written directions with minimal issues. IMO they should not ask a ton of expertise from a prep cook, but you should have a clue about common ingredients on the menu. If they have sauces on there, know the basics about them.
I've had guys that asked me nothing, I came in, they told me the job, asked me if I wanted it, and then they had me cut stuff and cook something, and then asked me if I wanted to do this.
I've had people only ask about how I liked jobs on my resume, and then expect nothing and show me everything they wanted from me.
Every interview I go to though, I am always ready to answer these because they're common if any HR theory is applied, and they have all come up many times.
Why do I want to work here. (Seeing if you are a good fit culturally, or really care)--> Nail this
What do you know about this company/restaurant/cuisine (see how much you care about getting this job) --> always mention the concept or highlights of the menu, you did read it, right?
If I could change one thing about my last job, what would it be (careful here, say something that would have made you a better worker or more productive, nothing petty or personal).
What is my greatest strength? (something that matches the position)
What is my greatest weakness? (something irrelevant to the position)
What would a previous employer say about me? (reliable, always on time, team player etc)
Name a difficult situation you had too overcome at work? (try to emphasize using people skills)
Have you applied elsewhere/been circulating your resume (yes is a good answer if they want you because they'll jump on you right away to snag you. But a bad answer if other Q/As lead them to believe you may not care that much about that job. Only say no if followed by this was the first place and you already contacted me, and wanting this position I didn't want to waste other people's time)
I was once asked if 1 TBSP of salt sounded reasonable for 8Qts of soup.
Know your meat temps and holding temps. Know how to deal with different meats, their cutting boards, and storing them properly.
Keep in mind many questions may not have a right answer, only a right way of addressing it. Do not come off as cocky even if you do know a lot. Do not come of as thinking you know if you don't. They want someone to come in with mouth closed, eyes open, ears tuned, hands moving, and willing to learn and do what is asked of them, nothing more. That is way more important than someone that "already knows everything", and possibly cannot learn more for their purposes. Typically they do not want artists and wannabe Gordon Ramsays (who would?). They want reliable and attentive workers. You'll show up and do what they tell you to do, and will improve over time. Prep cooks are an investment. Not only do they want you to get better at that job, but they will likely want you to be able to take on new responsibility.