In a large bowl, combine the green beans, cream of mushroom soup, milk, soy sauce, and black pepper. Stir until well combined.
Pour the mixture into a 9x13 inch baking dish.
Bake for 25 minutes.
Sprinkle 1 cup of French fried onions over the casserole. Return to the oven and bake for an additional 5 minutes, or until the onions are golden brown.
Remove from oven and top with the remaining 0.5 cup of French fried onions.