Like WTF!? "Starving? You can't afford 'good' food working here, but you can afford the food you're already making!"
Also, I worked in a lot of kitchens before and never once paid for a meal. "Damn son, didn't mean to put cheese on that! Guess I'll have to make another one."
Never pay a company for your food if you're the one making it.
Not sure, tbh some might be more likely to go in for a union if they aren't going to stick around as they are less likely to be bothered about the prospect of getting fired. Probably wouldn't want to pay union fees though so would need to be a free union. The real problem with that kind of work is how easy it is to replace people, especially in times of high unemployment.