You can do so many yummy things with leftover corned beef and cabbage, and this is a new favorite. You can keep it simple with just the basic recipe, or make sure to check out the notes for a Ruben version of the egg roll. Yum.
Here's another idea. If you like the texture of a traditional egg roll from a Chinese Restaurant, consider chopping all the ingredients in a food processor and using that as the filling. Whatever you do, give these a try.
FYI, here is a picture from the egg roll wrapper of how to fold an egg roll.