I've always thought that colcannon was a dish made of potatoes and cabbage. And almost all the recipes for it I've seen call for those two as the major ingredients. However (there's always a but, right?) I had, at different times this season, several visitors from Ireland. In each case I asked them about colcannon, and in each case they said (well, insisted, actually) that a proper colcannon is made with kale rather than cabbage. They also pointed out that colcannon is only served on Halloween night; something I'd not heard before. All these visitors stemmed from Dublin, as it turns out. So I'm wondering whether that's just a Dublin variation on the theme, or have we been making it wrong all these years? Anybody got any insights?