Preheat oven to 350°F (175°C).
In a mixing bowl, combine cream of mushroom soup, milk, soy sauce, and black pepper until smooth.
Add the blanched green beans to the sauce mixture and stir to coat evenly.
Transfer the mixture into a shallow oval casserole dish.
Bake uncovered for 25 minutes until hot and bubbly.
Sprinkle French fried onions evenly over the top.
Return to the oven and bake for an additional 5 minutes until the onions are golden brown and crispy.
Remove from oven and let rest for a few minutes before serving.