Begin by preheating the oven to 370F. Then, melt the butter and add all-purpose flour whisking continuously for 2 minutes.
2 tablespoon all purpose flour
Next, pour in the milk and use a spatula or whisk to stir the sauce thoroughly, ensuring there are no lumps. Add salt, soy sauce, and spices, and blend well. If the sauce appears too thick, incorporate more milk and continue stirring. The sauce will thicken even more once cooled.
1 cup milk, 2 tablespoon unsalted butter, ⅓ teaspoon salt or more to taste, ⅓ teaspoon pepper, ⅕ teaspoon nutmeg, 1 tablespoon soy sauce
Combine green beans, ⅔ cup of grated cheddar, and most of the fried onion (reserving 3 tablespoons) in a mixing bowl.
2 cups green beans, 1 cup grated cheddar, ½ cup fried onion
Pour the prepared sauce over the bean mixture and gently mix using a spatula.
Transfer the mixture to a baking dish approximately 12*12 inches in size. Bake for 25 minutes in the preheated oven.
After the initial bake, sprinkle the remaining cheese and crispy onions on top of the casserole, then bake for an additional 10 minutes until the top is golden brown.
Once done, allow to rest for 10-15 minutes and serve the hot casserole by slicing it into pieces and enjoy!