Preheat oven to 350° and get out a 9 inch square baking dish.

Place green beans in a colander and run water over them to thaw them out. Press gently with a towel to dry and add them to a large bowl.

Add the cream of mushroom, stir and pour into the baking dish.

Bake for 25 minutes.

While the casserole is baking, cook the bacon.

Cut the bacon into small pieces and cook in a skillet until crispy.

Remove the casserole from the oven and sprinkle the cooked bacon on top of the green beans. Bake another 10-15 minutes.