Preheat your oven to 350°F (175°C).
In a large mixing bowl, stir together the cream of mushroom soup, milk, soy sauce, and black pepper until well combined.
Add the green beans and 2/3 cup of the crispy fried onions. Gently mix everything together.
Pour the mixture into a 9x9-inch (or similar-sized) baking dish and spread it out evenly.
Bake uncovered for 25 minutes.
Remove the casserole from the oven, sprinkle the remaining crispy onions on top, and return to the oven.
Bake for another 5–10 minutes, or until the onions are golden and crispy.
Serve warm and enjoy the creamy, crunchy goodness!