I'm currently writing about a section in which the restaurant worker discovers a secret about the meat being sold. In my head I thought of writing that he overheard two drivers (who were responsible of transporting the meat from the farm) speaking in a language that he somehow understood just because his mother was of the same ethnicity but that just seems too coincidental. Anyone has anything better?
I think, at least in the U.S., it would be pretty rare for a restaurant to get its meat from the farm (unless that is part of your plot). Generally the animals go from the farm to a centralized slaughterhouse which ship meat to distributors who then wholesale it to retailers including restaurants. During this process animals are inspected for disease and the meat is kept at safe temperatures. I suppose, if you are intending the drivers to say they got it from a farm, it would be an illegal slaughter operation without any of the safety protocols, which would be a nasty secret. There are a few farms like Tyson chicken that do all the processes themselves but even then it is usually separate facilities. Even if his mother was of an ethnicity, it doesn't mean he speaks the language, unless she taught him. I know several Hispanic people who don't speak a word of Spanish and I also have a friend who is completely Caucasian but was raised in Japan from birth to age fifteen and speaks flawless Japanese. The device is really up to you as to the how and why your character understands the foreign language. Sometimes, multilingual people will assume someone who they think shouldn't understand the language doesn't which makes them more likely to speak freely in the supposedly "safe" environment. Take my friend who speaks Japanese: he is six foot six with a bleached mohawk who wears rock-n-roll shirts and baggy jeans. Not the guy you would pick in a crowd to speak Japanese. He was in a U.S. national monument where some Japanese school kids were touring. For some reason they were not paying attention to the exhibits but rather were making fun of peoples' body sizes in Japanese. My friend walked up and said something along the lines of "Why are you being so rude? Where is your chaperone?" in Japanese. Those kids were so embarrassed that someone could understand them, they apologized and left.
I like the language bit, and I agree with @Joe_Hall on how the language could be something the delivery drivers wouldn't expect your MC to understand. Could he stumble upon some documentation that seems questionable? Maybe in the language that he happens to be fluent in, but kept it secret (for whatever reasons). Or, what if he overhears customers who are gossiping while eating the food? They could be discussing farfetched rumors they'd read/heard about the neighborhood/area/meat supplier etc.
