Lightly spray the inside of your crock pot with nonstick cooking spray or line it with a slow cooker liner.

In a large mixing bowl, drain the cut green beans and add them to your prepared crock pot.

Whisk together the cream of mushroom soup, milk, salt, black pepper, and onion powder until smooth.

Gently fold in half of the crispy French-fried onions, then pour the mixture over the green beans.

Cover the crock pot and cook on low for 2-3 hours or high for 1 hour.

Remove the lid and sprinkle the remaining French-fried onions on top of the casserole.

Let it sit uncovered for a few minutes, then serve warm.