As a history teacher and anthropology buff, I find reading threads on authenticity extremely interesting. However, I have yet to find someone to point out the obvious. Authenticity, with rare exceptions, does not exist!
How can I come to this conclusion? People have been migrating since paleolithic times (at least 40-50 thousand years ago by boat, and probably up to 100,000 years or more by foot). When people migrate, they create cultural diffusion through trade and exchange of ideas. Obviously, this movement of people has only dramatically increased in the last few centuries.
Take "Italian" food for example. Can you imagine pizza sans tomatoes? Tomatoes were introduced from the New World, and most Europeans were afraid to use them for a long time due to fear they were poisonous. Even the ancient Romans imported spices and exotic ingredients from all over the known world, making an "authentic" ancient Roman recipe hard to find.
Indian food? It has been hugely influenced by the colonizing British.
Ok, how about West African food. Surely they have dishes that are more "authentically" African, without a big European influence. Actually, that would be hard to prove since all of Africa save for Ethiopia was colonized by Europeans in the 19th century (and then Ethiopia was invaded by the Italians who brought spaghetti in WWII). Even if you can find dishes that seem "authentic" , you foget that West Africa has had a LONG history of trade! Maili, Songhai and other Empires ruled the area, trading all over Africa and even to the Middle East!