Crock-Pot Green Bean Casserole from Nashville Kat

3 – 12 ounce packages frozen green beans, thawed

1 packed cup shredded Cheddar

½ cup butter

2 tablespoons flour

1 ½ teaspoons salt

½ teaspoon black pepper

1 teaspoon brown sugar

1 cup sour cream

1 large can french fried onions

Melt butter in large skillet then whisk in flour and cook for one minute. Add beans, salt, pepper and sugar and cook a few minutes just to warm the beans. Pour into a large bowl and toss with sour cream and Cheddar. Pour into crock and cook on high 1 ½ hours, then stir and cook on low 1 ½ hours. Sprinkle package of fried onions on top and serve.