1. If using frozen green beans, be sure to thaw them completely and drain any excess liquid. If using fresh beans, trim and cut them into 2-inch pieces, then briefly blanch them in salted boiling water before draining. If using canned beans, simply drain them well.

2. Preheat your oven to 350°F.

3. In a large mixing bowl, whisk together the condensed cream of mushroom soup, milk, and soy sauce until smooth and well combined.

4. Add the drained green beans, 2/3 cup of the fried onions, and black pepper to the soup mixture. Gently fold everything together until the green beans are evenly coated with the creamy sauce.

5. Pour the green bean mixture into a 9×9-inch baking dish and spread it into an even layer.

6. Bake the casserole for 25 minutes, until the mixture is bubbling around the edges and heated through.

7. Remove the casserole from the oven, give it a gentle stir, and then top it with the remaining 1/3 cup of fried onions, spreading them evenly across the surface.

8. Return the casserole to the oven and bake for an additional 5 minutes, until the onions are golden and the dish is gently bubbling.