Set out a large 6+ quart slow cooker. Pour in the frozen green beans. Add the cream cheese, sour cream, milk, cheddar cheese, onion soup mix, garlic powder, ½ teaspoon salt, and ¼ teaspoon black pepper.
Stir to combine. Then spread the mixture evenly in the crock and wipe the sides of the crock clean. Cover and set on HIGH for 2-3 hours, or on LOW for 4-6 hours.
Stir well. Then sprinkle the top with crunchy fried onions and serve warm.
You can add as many fried onions to the top as you like. I usually sprinkle about half the container over the top.