Preheat the oven: Preheat your oven to 350°F (175°C). This temperature allows the casserole to cook evenly while developing a golden top without burning the cheese or onions.

Brown the beef: In a large skillet over medium heat, brown the ground beef until fully cooked, breaking it apart with a spatula as it cooks. Once browned, drain the excess fat to prevent your casserole from becoming greasy.

Combine ingredients: In a large mixing bowl, combine the cooked ground beef, drained green beans, cream of mushroom soup, milk, garlic powder, onion powder, salt, and pepper. Stir thoroughly until all ingredients are well incorporated and evenly coated with the soup mixture.

Prepare the baking dish: Transfer the mixture to a greased 9×13 inch baking dish and spread it evenly to ensure consistent cooking and proper heat distribution throughout the casserole.

Add cheese topping: Sprinkle the shredded cheddar cheese evenly over the top of the mixture, creating a delicious melty layer that will brown beautifully in the oven.

Initial bake: Bake the casserole for 25 minutes until the mixture is hot and bubbly and the cheese is completely melted. The edges should start to show slight browning.

Add crispy onion layer: Remove the casserole from the oven, evenly sprinkle the French fried onions on top, then return it to the oven for an additional 5-10 minutes until the onions are golden brown and crispy.