Braise. I use my crockpot, make a base of vegetables (carrots, celery, sometimes potatoes), place the meat on top and cover with water. Cook on low for 8+ hours. The resulting broth is delicious for making lentil or bean soups, or 'Reuben Soup'--cut the leftover corned beef, carrots, cabbage (or sauerkraut) and potatoes into bite-sized pieces and heat in the broth (add water if too salty). Top individual bowls of soup with shredded Swiss cheese and rye croutons.
Per a different braise recipe (more of a dry-braise, to my mind, using a rack and very little water) I browned the beef WELL before - departing from that recipe - half-submerging in a covered roasting pan. It's braising away nicely at 225°.
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http://www.seriouseats.com/2014/03/how-to-make-the-best-corned-beef.html
There are others like Suzanne Goins who say boil.
https://food52.com/recipes/16596-suzanne-goin-s-corned-beef-and-cabbage-with-parsley-mustard-sauce
My personal preference would be to braise because I think low-and-slow is better for this cut of meat.
In the end, it's your call -- what you and your guests prefer. Clearly, people have enjoyed corned beef cooked both ways for well over a century.
Good luck.