I'm not a fan of the term "authentic" when it comes to describing cooking. What is "authentic Irish cooking."? Is it cooking? Is it done in Ireland by Irish citizens? Those are the only reasonable criteria. Thus, vindaloo is "authentic Irish food" so long as it's cooked in Ireland by Irish citizens. Anything else gets tangled up in all kinds of very nasty issues of history, politics, culture, and even race. In part, this is because we look upon "authentic" as a measure of "proper". "Authentic Irish food" is a code word for "proper Irish food", and if you cook anything different, you're not "properly Irish". This is true for any cuisine.

Likewise, who gets to define "authentic"? Do the Irish get to define "authentic", and who gets to define who is "Irish"? Is a man born and raised in Ireland, of parents immigrated from Bangledesh, not really "Irish"? If not, does that mean he can just be kicked out or otherwise excluded as not being "really" part of Ireland? These are issues that don't need to pollute something as wonderful as food.

Thus, I would propose we use terms like "traditional", "innovative", "recent", or specific identifiers like "around Offaly in the 1930s". I admit that one could argue over what constitutes "traditional". In much of the USA, "Irish" is confined to a strange little cartoon of the middle of the 1800s, with random Kennedys sprinkled on top.

Anyway, just throwing things in. Of course, it would be quite interesting to trace evolution of various common dishes of Ireland over the years from various sources.

Anyway, what constitutes a "traditional" food? When it comes to Ireland, I can't say, but to give an idea of how kooky even "traditional" can be, here is a list of some "traditional Indiana foods", taken from my own experience:

Chili with macaroni, flat beef roasts (usually chuck), meatloaf, "porcupine balls" (meatballs with rice in them), eggs and bacon, grilled cheese, hamburgers on bread (not buns), hot dogs split longitudinally and served in bread (not buns), chicken a-la king, spaghetti with marinara plus ground beef, beef stroganoff over noodles.

I know they're all traditional Indiana cooking because my grandma served them as everyday food without consulting recipe books, her family had been living in Indiana for 100 years, and what could be more traditional than that?