Once again, it is the head chef's job, not someone else's. As to the rest of your comment, that's easier said than done when there are a variety of kitchen positions in a restaurant with several people preparing the various parts of the menu. The head chef is ultimately responsible for the quality of the food being prepared in his kitchen.
The restaurant hired them. Must not have been very smart business people eh?
The moral to the story is don't violate other people's rights. And when you do don't make yourself out to look like the victim.
Is it really that simple? Can't we confuse the issue with just a little anti-immigration rhetoric?