In saucepan on top of stove, melt butter or margarine. Stir in onions and sauté until wilted. Stir in flour. When well mixed, whisk in chicken broth. Stir frequently over medium heat until broth is thickened.
Pour into slow cooker. Mix in remaining ingredients except cheese.
Cook on Low 4½ hours. About an hour before the end of the cooking time, stir