Ingredients:
2 (14.5 ounce) cans green beans, drained
1 (10.75 ounce) can condensed cream of mushroom soup
1 (6 ounce) can French fried onions
1 cup shredded Cheddar cheese
Directions:
Preheat oven to 350 degrees F (175 degrees C).
Place green beans and soup in a large microwave-safe bowl. Mix well and heat in the microwave on HIGH until warm (3 to 5 minutes). Stir in 1/2 cup of cheese and heat mixture for another 2 to 3 minutes. Transfer green bean mixture to a casserole dish and sprinkle with French fried onions and remaining cheese.
source:https://www.foodnetwork.com/recipes/alton-brown/best-ever-green-bean-casserole-recipe-1950575