Pretty darn simple. Fat side up on a rack in a roasting pan, cut slits into the fat, rub in the seasoning in the packet that comes with the corned beef. Cover and cook on low (250F-300F) all day. In the afternoon, I tossed in a package of Irish O'Garlic sausages, covered and left in the oven until dinner. I removed the foil cover during the last bit of cooking to brown. I served it with new potatoes and peas in heavy cream.