Bring a large pot of water to a boil. Add the green beans and cook for 5 minutes until they turn bright green and soften slightly. Drain and set aside.
Preheat the oven to 350 degrees. In a mixing bowl, stir together the cream of mushroom soup, milk, soy sauce, and black pepper until smooth.
Add the drained green beans and 1 cup of the French fried onions to the bowl. Stir until the beans are coated evenly.
Transfer the mixture to a 1.5-quart baking dish. Spread it into an even layer.
Bake for 25 minutes. Remove the dish from the oven and sprinkle the remaining 1/2 cup of French fried onions over the top.
Return the dish to the oven and bake for 5 more minutes until the onions on top turn golden.