Lightly grease the inside of your slow cooker insert.

In a large bowl, combine the thawed hash browns, cream of chicken soup, sour cream, ¾ cup of the shredded cheddar cheese, milk, salt, and pepper. Mix until everything is evenly coated.

Transfer the potato mixture to the prepared slow cooker. Spread it into an even layer.

Cover the slow cooker and cook on LOW for 3 to 4 hours, or on HIGH for 1.5 to 2 hours, until the potatoes are tender and the mixture is hot throughout.

Stir the mixture gently about 30 minutes before serving.

Sprinkle the remaining ¼ cup of cheddar cheese over the top during the last 15 minutes of cooking, or until melted and bubbly.

Serve hot directly from the slow cooker.