Sometimes corned beef becomes tough and hard to chew when it is roasted, fried or slow boiled on a heat that is too low. Tough corned beef can be fixed, and keeps it from having to be thrown away.
Peel and dice onion.
Cut head of cabbage in half.
Place the tough, cooked corned beef into the stock pot. Add the onion and cabbage.
Pour a gallon of water into the pot.
Cover the pan and set stove to a medium heat, or about 325 degrees Fahrenheit. Corned beef must be heated at above 250 degrees Fahrenheit, so that the tough, stringy meat will separate. Simmering it in this manner can revive its taste and texture.
Let the corned beef simmer for about 30 minutes. This finishes the cooking process and makes it tender. The onions and cabbage add to the flavor of the meat, and can be eaten.
Remove the corned beef from the pot and turn off the stove. Thinly slice the meat on a platter and serve.