Reuben Casserole

Ingredients

• 1, 16 ounce carton sour cream
• 1 large onion, chopped
• 4 tablespoons Thousand Island dressing
• 1, 26 ounce jar sauerkraut, drained
• 2 cans corned beef, sliced
• 12 ounces Swiss cheese, shredded
• rye bread crumbs
• 1 stick butter, melted