Corned Beef Sandwiches with Colcannon

Sunday March 18
The reason for making two corned beef briskets on St. Patrick's day becomes clear the day after. They shrink unbelievably while cooking. So you need at least one big one (ca. 4 lbs.) to actually slice and serve on the day, especially if you want to provide a doggy bag or two for your guests, and a whole nother brisket for sandwiches and hash for yourselves. In fact, cold corned beef sandwiches may be the only reason for ever boiling corned beef - as below, it's a Jewish thing.
So the next day, we did the obvious and made those sandwiches, with Holt's olive-oil bread, and slathered with mustard and cole slaw; sour pickles on the side. You should be drooling now; I am.
There was also leftover vedge, and the best solution to these particular sorts is Colcannon (Irish: cál ceannan, white head), known in England as Bubble-and-Squeak (write your own joke here). You chop up the leftover cabbage and mash it together with the soft potatoes and carrots, using cream or butter to grease the ways. Following the example of my good friend Phoebe, with whom I was snowed in one memorable week in Walla Walla, season this mush liberally with salt, pepper, nutmeg, and cayenne. Pile it in a buttered casserole and nuke the crap out of it; when it's hot, sprinkle some breadcrumbs on top and crisp it under the broiler for a couple of minutes.
Preparing the sandwiches takes a fraction of the time that the Colcannon does. You may have the patience to wait and eat the one with the other. We didn't.