Place meat in an 8-quart Dutch oven and put in enough water to cover meat. Bring to a boil. Reduce heat to low, cover and simmer 2 hours or until brisket is almost tender. Add red potatoes., carrots and rutabagas. Continue to simmer for 20 minutes.
Add cabbage, return to boil. Reduce heat, cover and simmer for 10-15 minutes longer or until vegetables are fork tender. Remove corned beef and slice thin and diagonally against the grain.
Serve with either high quality mustard, whole grain mustard horseradish or Harris Ranch Horseradish.