Preheat your oven to 350°F.

In a large bowl, whisk together the cream of mushroom soup, milk, salt, and pepper until smooth.

Add the green beans and half of the fried onions. Stir until everything is coated.

Transfer the mixture to a baking dish and spread it out evenly.

Bake uncovered for about 40 minutes.

Remove from the oven, give it a gentle stir, and sprinkle the remaining fried onions on top.

Return to the oven and bake for another 10 minutes, or until the topping is golden and crisp.

Serve warm.