I have always lived among the Irish. I grew up in Boston, a legendary Celtic hub, and settled in Missoula, Montana, 100 miles downstream from America’s most Irish city per capita: Butte. I used to credit my affinity for that feisty tribe to this coincidental geographic overlap, but now I see a deeper connection. And you can see it by looking no further than the nearest bowl of corned beef and cabbage. For a time, Ireland exported some of the world’s finest corned beef. It was a pricey treat, and it never caught on in the with the frugal Irish, who preferred lamb and pork to beef anyway. Corned beef and cabbage became an American Irish delicacy in Boston and New York, where immigrants from the Emerald Isle found themselves in Jewish neighborhoods, with the means to bring home a corned brisket from the local delicatessen once in a while …