Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the drained green beans, cream of mushroom soup, milk, garlic powder, onion powder, salt, and pepper. Stir until well mixed.
Fold in ¾ cup of the shredded cheddar cheese into the mixture.
Pour the green bean mixture into a greased 9x13-inch baking dish.
Bake in the preheated oven for 25 minutes.
Remove the casserole from the oven and sprinkle the remaining cheddar cheese and French fried onions on top.
Return to the oven and bake for an additional 10-15 minutes, or until the cheese is melted and bubbly and the onions are golden brown.
Let it cool for a few minutes before serving.