Corned Beef and Cabbage Casserole

1 small cabbage
2 tablespoons butter or margarine
1/2 cup chopped onion
1 (12 ounce) can corned beef
3 tablespoons butter or margarine
3 tablespoons flour
1 1/2 cups milk
1/2 teaspoon salt
1/8 teaspoon pepper
2 tablespoons butter or margarine
1 cup fine bread crumbs

Cut cabbage in half and each half into 3 pieces. Remove core and boil in salted water for 20 minutes. Drain and put in bottom of a 1 1/2-quart casserole dish.

Melt 2 tablespoons butter in frying pan. Add onion and corned beef and saute. Break up corned beef and continue sauteeing until onion is clear. Pour mixture over cabbage.

Melt 3 tablespoons butter in a medium saucepan. Stir in flour, then add milk and salt and pepper and bring to a boil while stirring. Pour over meat mixture.

Melt 2 tablespoons butter in a small saucepan. Stir in crumbs to blend and sprinkle over top of sauce.

Bake uncovered at 250 degrees F for 30 minutes.