You wont really (at least I didn't get any "Difficult" questions but you just have to know the position wants and how you fit in. One could be "how did you hear about this job? although not difficult, try to remember where you actually heard about the job...stuff like that. If you have experience in the field, sell it. They are looking for "foodies" and those interested in the culture of what it is they do. make sure you know the company and what they do as well. and how your experience ties in.
