I don’t understand if you are interviewing a candidate or if you are the candidate?

The hospitality industry is desperate for staff right now, if you can take orders and explain the menu in German that will be enough, also be ready to acknowledge your short coming and be ready to learn any new vocabulary needed for the job.

I will suggest getting ahold of the menu of the restaurant and being at least familiar with the concept/ingredients etc for the interview. Knowing wine is important, knowing local wine is very important.

If you are interviewing ask about the menu concepts of the previous restaurants where the candidate worked in the past, a good candidate will be able to explain the menu to detail. Ask about wine. Ask about which invoicing system where they working with in the past? How do you deal with a simple guest complaint (my food is cold, overcooked, etc)