Preheat your oven to 375°F (190°C) and grease a baking dish with cooking spray.
Bring a pot of water to a boil. Add the green beans and cook for about 5 minutes until they are tender-crisp. Drain and set aside.
In a large skillet, melt the butter over medium heat. Add the diced onion and minced garlic, sautéing until the onion is translucent.
Sprinkle in the flour and cook, stirring, for 2-3 minutes until the mixture is golden brown.
Gradually whisk in the chicken or vegetable broth and whole milk, cooking until the sauce thickens. Season with salt and pepper.
Stir in the cooked green beans and half of the grated cheddar cheese, mixing well to combine.
Pour the mixture into the prepared baking dish, topping with the remaining cheese and fried onions.
Bake for 20-25 minutes until bubbly and golden brown.
Let the casserole cool slightly before serving and enjoy the homemade goodness!
This casserole can be stored in an airtight container in the refrigerator for up to 3 days.
To reheat, cover with foil and bake in a 350°F (175°C) oven for about 15-20 minutes, or until heated through.
Feel free to add your favorite ingredients such as mushrooms, diced bell peppers, or spices to enhance the flavor.
Find it online: https://www.chyachya.com/creamy-green-bean-casserole/