Something a buddy came up with when we used to hold down the night shift in the 81st Brigade Clearing Station, back in the 80's:
1 can corned beef
1 can sauerkraut
Wasabi mustard to taste
Heat the whole mess in a mess kit over one of those tin stoves in a GP Medium tent- serve with canteen water or coffee, depending on what's available. Good with MRE or C-Ration crackers, too. Sounds weird, but really tasty, especially at about 0200 with the Yakima wind howling outside.
Another good use for corned beef is the Reuben sandwich, probably my favourite way to enjoy it. The sandwich works equally well with pastrami, but the rye bread, sauerkraut, swiss cheese, and thousand island dressing are not negotiable. Pan-fried with butter, until the cheese is nice and melty.
I skip the thousand island cause it's too sweet and gloppy for me. If I make them at home I sub in some good hot mustard, if I order one I just order the dressing on the side.