Slow Cooker Green Bean Casserole

2 (16 ounce) packages frozen cut green beans

2 (10.75 ounce) cans cream of chicken soup

⅔ cup milk

½ cup grated Parmesan cheese

¼ teaspoon salt

¼ teaspoon ground black pepper

1 (6 ounce) can French-fried onions, divided

Combine green beans, cream of chicken soup, milk, Parmesan cheese, salt, black pepper, and half the can of French-fried onions in a slow cooker.

Cover and cook on Low for 5 to 6 hours. Top casserole with remaining French-fried onions to serve.