I like it in an oven bag,too. This recipe is from Reynolds-and their photo, also. It's very easy.
Corned Beef and Cabbage
1 Reynolds® Oven Bag, Large Size
1 tablespoon flour
1/2 cup water
1 corned beef brisket, about 2 1/2 pounds
1/2 teaspoon ground allspice
1/2 teaspoon salt
1/2 teaspoon pepper
1 head cabbage, cut in 6 wedges
1 large onion, cut in 6 wedges
3 large carrots, cut in half crosswise and then lengthwise
PREHEAT oven to 350°F.
SHAKE flour in Reynolds Oven Bag; place in 13x9-inch baking pan. Add water to oven bag. Squeeze bag to blend in flour.
ADD beef to bag, fat side up. Sprinkle allspice, salt and pepper over meat. Place vegetables around beef.
CLOSE oven bag with nylon tie; cut six 1/2-inch slits in top.
BAKE 2 to 2 1/2 hours or until fork-tender. Let stand 10 minutes. Remove and toss top leaf from cabbage. Slice beef and serve with vegetables and meat juices.
TIP: If a seasoning packet is included in your corned beef package, substitute it for the allspice, salt and pepper.