I can understand asking someone this if you know they have ties to a particular culture and they would know "real" cuisine . . . but definitely not if I didn't know the person fairly well already! A third-generation Vietnamese-American friend of mine (living in an area where Asian people were fairly uncommon at the time) always got asked about her suggestions for good Chinese food. First of all, she's a full-blooded American, never been out of North America, and other than the color of her skin, doesn't have any particular connection to Asian culture or customs. Second, Vietnam and China are two totally different countries, so even if she did know, it would be about the wrong place. Thirdly, she grew up on good ol' McDonalds like the rest of us Americans because her parents didn't like to cook, so she wouldn't have been able to tell you what "authentic" Vietnamese food tastes like!