The Best 3-Cheese Green Bean Casserole

1 Preheat oven to 350°F.
2 In a medium skillet on medium-high heat, add oil and sauté onions until soft and translucent. Set aside.
3 In a large bowl, combine cream of mushroom soup, milk, soy sauce, black pepper, garlic powder, sautéed onions, green beans, ¼ cup of each kind of cheese, and 1 1/3 cups crispy fried onions. Add to a in 3-qt. baking dish and top with the remaining crispy fried onions and cheese.
4 Bake uncovered for about 25-30 minutes, or until bean mixture is hot and bubbling, and onions are golden brown.