This can’t really be answered in a simple way. Like a lot of “traditional” European dishes use potatoes. But at some point they where not native to Europe. So does that count? Or something like New York style pizza, is that American? Because in that case the Netherlands for example has a lot of Indonesian dishes that are more variations on traditional Indonesian food (made by immigrants using more local ingredients).

I think food is the best example why immigration and mixing of cultures can really improve humanity.