Mushrooms au Gratin

1/2 pounds mushrooms, washed and drained
1/4 cup butter
1/4 cup sour cream
1 tablespoon flour
1/2 cup shredded Cheddar cheese

Sauté mushrooms in butter. Place in a baking dish. Mix sour cream, flour and Cheddar cheese and pour over the top of mushrooms. Bake at 350 degrees F until hot and bubbly.