Preheat the oven to 350°F.
In a large bowl, mix green beans, soups, milk, salt, and pepper and pour into a lightly greased 9×13-inch baking dish.
Bake for 18–20 minutes.
Top with onions and bake for 5 minutes more.
Learn how to make green bean casserole, a holiday classic, featuring sauce-covered green beans and crispy onions baked to golden perfection.