Remove the corned beef from its package. Save the spice package for something else.

Wash the brisket well in cold water.

Fill a large stockpot with water. Cut the onion in half.

Put the brisket and onion in the water.

Heat on medium heat and cook for two hours or until the brisket is tender.

Remove the brisket from the water and pat dry. Let the brisket cool in the refrigerator.

Start your barbecue up and prepare it for indirect cooking.

If your sauce is not too sweet, you may put the sauce on before putting the meat on the barbecue.

Put the meat on the grill using indirect heat. Roast on slow heat for two hours, basting occasionally and checking that the coals are still hot.

If your sauce is sweet, wait until the last fifteen minutes before putting it on.