I have cooked this lots of ways, and my favorite method is in the slow cooker. Just place the UNdrained corned beef and the seasonings in the cooker, slice cabbage into wedges of a size to fit on top of the roast, and cook on whichever temp your cooker has. I usually cook it in about 4 hrs on high. I also add lots of carrots and tiny red potatoes an hour or so before serving. It's similar to New England Boiled Dinner, but without the turnips (which are also good!)
Hope this helps!
Robin Alwine