Corned Beef and Cabbage Casserole

1 small head cabbage, cored and cut into large chunks

¼ cup butter

2 (12 ounce) cans corned beef

½ onion, finely chopped

⅓ cup butter

⅓ cup all-purpose flour

2 ½ cups milk

1 teaspoon salt

1 pinch ground black pepper

Preheat oven to 350 degrees F (175 degrees C).

Bring cabbage pieces to a boil in a pot and simmer until just tender, about 5 minutes. Drain, then transfer cabbage to a 2-quart baking dish.

Melt 1/4 cup butter in a skillet over medium heat. Stir in corned beef and onion; cook and stir until the onion has softened and turned translucent, about 5 minutes. Break up any large chunks of corned beef.

Spread corned beef mixture over cabbage.

Melt remaining 1/3 cup butter in the same skillet over medium heat; whisk in flour.

Pour in milk and season with salt and pepper. Continue whisking until sauce comes to a simmer and is thickened, about 5 minutes.

Pour sauce over corned beef and cabbage mixture.

Bake in the preheated oven until bubbly, about 30 minutes.