Preheat your oven to 350°F.

In a large pot of boiling salted water, blanch the green beans for 5 minutes. Drain and transfer them to a bowl of ice water to stop the cooking process. Once cooled, drain again and set aside.

In a large skillet over medium heat, sauté the onions and mushrooms in a bit of oil for about 5-7 minutes until softened. Add the garlic and cook for an additional minute.

In a large bowl, combine the sour cream, cream of mushroom soup, Worcestershire sauce, soy sauce, salt, and pepper. Stir in the sautéed onion and mushroom mixture, followed by the blanched green beans and half of the shredded cheddar cheese. Mix until well combined.

Transfer the mixture to a greased 9x13-inch baking dish. Top with the remaining cheddar cheese and crispy fried onions.

Bake in the preheated oven for 25-30 minutes, or until the casserole is bubbly and the top is golden brown. Let it cool for 5 minutes before serving.