Coordinating cooking times of various ingredients maintains color, texture and vitamin content. Corned beef brisket requires long, medium-temperature cooking in liquid to make it tender and tasty. Starchy vegetables, such as potatoes and carrots, become mushy long before the meat finishes cooking. If you braise the brisket instead of boiling it, the cabbage scorches. Cooking the vegetables separately from the meat also ensures that your vegetarian and vegan friends can enjoy the meal without worry.
Braising and boiling work best when making corned beef. Braising, or pot-roasting, means slow-roasting meat in liquid after browning it in fat. The USDA Food Safety and Inspection Service recommends braising at 350 degrees Fahrenheit for at least one hour per pound of corned beef brisket. A 3-lb. brisket needs three hours to cook, while potatoes take as few as 20 minutes, depending on the cooking method. Carrots cook in three to 45 minutes, depending on the cooking method and whether the carrots are whole or sliced. Cabbage boils in four to nine minutes when sliced thick or chopped, while braising takes up to 1 1/2 hours, depending on the type of cabbage.
The corned beef should thaw completely before cooking. Because it cooks the longest, it needs to go into the oven or slow cooker before you start the other vegetables in their own pan. Red cabbage, which needs 1 1/2 hours to cook, can go into a pan with a cup of braising liquid about halfway through the cooking time needed for the corned beef, while green cabbage can begin cooking at the same time as the carrots and potatoes, about three-fourths of the way through the corned beef cooking time.
If you are serving vegetarian or vegan friends, use vegetable stock, apple juice, red wine or brandy as your braising liquid, not chicken or beef stock. Use drinking-quality alcohol, not cooking wine. Cooking-quality alcohol contains added salt and chemicals that give food an off taste.
You can make vegetable stock from diced onions, celery, carrot, tomato, garlic and 2 qts. water, with a little lemon juice, hot sauce and salt for flavor. Boil the stock until the vegetables tenderize and the stock has a full-bodied scent.
Allow corned beef brisket to rest before carving or make it the day before serving so that it has time to chill. Cold corned beef is easier to slice into even thicknesses. Reheated corned beef should cook to 165 degrees Fahrenheit as measured with a food thermometer. Serve a 1/2-inch thick slice of corned beef with 1/2 cup each of carrots, potatoes and cabbage.