Our tablemates on our first cruise were of Indian descent and so were our servers. They were also vegetarian. They requested "whatever you [the servers] eat will be fine". Every night we were treated to family-style fresh made Indian food along with our dinner selections. It was AMAZING. The best Indian food I've ever had.
Apparently, on their previous cruise they asked their servers what the crew ate and their servers mentioned that many of the cooks cooked Indian food for the Indian crew members. Since it didn't add any trouble, the servers on that ship brought them food every night, so they made the same request on our cruise.
Ok, so Ive also seen this done with Filipino food as many of the kitchen and server crew are Filipino. Because of limited availability, they can only prep 1 or 2 dishes. On two of our cruises, we sat near other Filipino families who made this request. One dish available is chicken cooked in soy sauce and vinegar. The other is a sour soup which our Filipino waiter said doesnt taste quite authentic anyway onboard because they dont have all the true ingredients and just sub whatever they have. I heard 1 family say they were from Los Angeles. I find making this request odd because Filipino food in Los Angeles can be cheap. super cheap. and readily available. so making this request on a pricey cruise when seafood and steak and other gourmet meals are available is odd to me.