Corned Beef with Irish Flag Vegetables

I tried this recipe for corned beef & vegetables this St. Patrick's Day. There are no amounts for the vegetables -- just make enough for the people you are serving. The more vegetables you have, the bigger the platter you will need to make the Irish flag.
1 piece of corned beef brisket (about 5 lbs.)
Boiling water
1 Tbsp mixed pickling spices (or use the little packet that comes with the meat)
1/2 cup firmly packed brown sugar
1/3 cup prepared mustard
1 head cabbage, cored and cut into 6 wedges
Potatoes, peeled and cut in half (or quartered if very large)
Baby carrots
Melted butter (enough to pour on carrots and potatoes)
Chopped parsley
Salt & Pepper

Preheat oven to 325. Place the corned beef in a large roasting pan and sprinkle with pickling spices. Pour enough boiling water into the pan to cover the meat. Cover pan tightly with aluminum foil and bake for two hours or until tender when pierced with a large fork. Remove from oven and allow meat to cool in cooking liquid. (Meat can be cooked to this point the day before and kept in cooking liquid in refrigerator).

About 1 hour before serving, drain the beef and reserve the cooking liquid. Place the beef  back into the pan and bake for 30 minutes at 325. Combine the mustard and brown sugar in small bowl. Pour over meat and continue to bake for 30 more minutes or until meat is nicely glazed. Remove from oven and slice thinly across the grain.

Meanwhile while meat is cooking, put potatoes in a large pot and cover with salted water. Bring to a boil and boil potatoes for 20-30 minutes or until tender when pierced with a fork. In a separate pot, bring reserved cooking liquid to a boil. Place cabbage and carrots in cooking liquid and add enough boiling water to cover vegetables. Boil vegetables for 20-30 minutes or until tender.

Drain potatoes and vegetables. On a large rectangular platter, arrange vegetables in three vertical rows with cabbage on one side, potatoes in the middle and carrots on the other side, resembling the Irish flag. Pour melted butter over carrots and potatoes. Sprinkle entire platter with chopped parsley and salt and pepper.