My dad used to work on the Western Bagel trucks in Van Nuys on Sat mornings from 0'dark-thirty to maybe 7am. So every Sat morning for several years, he would bring a bag of still warm bagels. I think that is one reason I still love bagels today. My only requirement is that the shop use salt as one of the "everythings" in the everything bagel.

My idea of "authentic" can be summed up in three questions:
1) Does the chef know how to cook in the style and taste most common in the place the style originated?
2) Does the location of the resto permit the chef to use the proper ingredients? (i.e., can the chef get the required spices, mushrooms, breads, etc.)
3) Do the local tastes allow the recipes to remain unmodified or do they require them to be changed? (i.e., spice level, fat level, etc.)

If the answer is "yes" to all three, it's "authentic" in my mind. It might not be good, but it's authentic. It's just authentically bad. And the first does not preclude Italian cooking from being developed in the US. Buca de Beppo says it the best when they advertise "Italian Immigrant Dining". It's not Italian, it's Italian-American or Italian-Immigrant, which is a style in and of itself. So using the three questions, if you have an Italian-American recipe with the knowledge to make it, you have the proper ingredients, and you stay true to the recipe, it's authentic.