The flavor is of course going to change dramatically by corning it, lots of salt and spices and such involved there, but I’m not terribly concerned about that, it isn’t really the most flavorful cut to begin with, not a lot of fat and connective tissue to give it flavor, which is also why it’s so tender which is the real draw

In general my plan is to cure it, but otherwise treat it like I would a normal wellington, so overcooking hopefully shouldn’t be a problem- quick sear, wrap it up then cook to probably medium-ish (normally aim more rare/medium-rare for Wellington, but rare corned beef just kind of doesn’t sound great to me)

And yeah I think the pudding instead of or mixed into the duxelles is a good move, not easy to find around me but I’ll be looking around for it and I have almost 2 weeks to track it down