Delicious, cheesy Reuben Casserole

Ingredients

• 1/2 cup butter, melted
• 1/2 cup all-purpose flour
• 3 cups milk
• 1 teaspoon garlic powder
• 1 teaspoon onion powder
• 1 teaspoon salt
• 1/2 teaspoon black pepper
• 2 cups sauerkraut, drained
• 2 cups cooked corned beef, chopped
• 2 cups Swiss cheese, shredded
• 1 cup rye bread crumbs