Have you ever noticed that when people say they want a certain kind of food, they often omit the word "food" altogether? Instead they say "Let's eat some Italian," or "I could go for some Indian."
It sounds like they plan to go out and cannibalize someone of that particular nationality.
For instance, when someone says
I picture this:
What you mean is Mexican food. You want to eat some Mexican food. Not tear your teeth into the flesh of some unfortunate man who happens to be from Mexico.
So next time someone asks, "Do you want some Chinese?" your response should be, "Absolutely not! That is disgusting and wrong!" and you should probably run away before you, too, are eaten.