I mean, that's what happens as a cuisine gets passed down from generation to generation: it evolves. Cuisine and language are similar in that respect. The sort of English spoken in the US is no less "real" than the sort of English spoken in England; why would the Chinese food made and sold by the descendants of Chinese immigrants in the US be any less "real" than the Chinese food made and sold in China? They both evolved from the same point, and simply diverged and evolved.

And that's what we're seeing now with Thai food. As the generations get further and further removed from the original immigrants, the cuisine continues to evolve in its own direction. And why shouldn't it?

It's also worth remembering that restaurants are not always (and in fact, rarely are) representative of the actual local cuisines. There's still heavy emphasis on the good ol' home cooked meal (as hard as frozen food chains might try to supplant home cooking), and that's where you see both the preservation of tradition and the proliferation of experimentation, marketability and profit be damned. Indeed, looking at these home cooked meals, it becomes readily evident that the oft-denigrated Chinese holes-in-the-wall and small town pizzerias are far closer to authenticity than the fancy gastropubs and fusion restaurants of snobbish preference; authentic cuisine puts form over function, and heartiness over presentation. Authenticity comes from humility and self-awareness; it doesn't need to try to impress anyone's palate.

It’s the speed of change that suggests it’s more than just the natural evolution of food. I am not saying it’s a purely negative effect, just describing what’s happens when a new ethnic food gets introduced to the American pallet.

I stand by my original point that you can’t call something authentic X after you significantly later what it is. Small town pizzerias and snobbish restaurants are both very distinct from classic Italian food.

That said, if you go to Italy today they very much cater to tourists expecting food their familiar with. Further, while the tomato was only imported in the 16th century, that’s plenty far back to confuse the issue.

And pretty much any Italian dish you make with meat, is American Italian. Made by Italian-Americans once they got to America and meat was plentiful.

So does that make it "not Italian"? It was first-generation cooks that made it. Certainly not "Traditional Italian" but so what?

Yeah the guy we know at our favorite Indian place says "You know this is Restaurant Indian Food. Some time ask me, and I'll have Mom make you the stuff we eat at home!"

So we're gonna ask the next time.