How Long To Boil Corned Beef Cabbage And Potatoes. When it's reached a boil, reduce the heat to low, cover with a lid and let simmer for 2.5 hours. Slice corned beef against the grain and serve with cabbage, potatoes, and carrots.
Add the garlic and onion. How to cook corned beef and cabbage and potatoes. Continue cooking at 325°f (162°c) for a further 2 hours (or 1 hour per pound of corned beef) after covering and returning the roasting pan to the center of your oven.