Found this recipe on the web and it looked so good I am going to try it.

Baked Corned Beef

1 corned beef (5 lbs)
1/2 to 1 C. Dijon mustard
1/2 C. brown sugar
Preheat oven to 375 degrees. Open packaged corned beef and rinse well. Discard spice packet. Place the corned beef flat side up on top of foil (you will be wrapping the corned beef with the foil.) Spread mustard onto the corned beef, then sprinkle with brown sugar. Wrap the brisket tight with foil. Place the wrapped brisket in a baking dish, and place in the oven. Cook for approximately 2 and 1/2 hours, unwrap the top of the brisket, and turn the oven onto broil, and broil long enough for the mustard crust to brown.