Melt 2 tablespoons of the butter in skillet. Add 1 tablespoon of the flour, whisking until smooth. Add wine, and cook, stirring and scraping to loosen browned bits from bottom of skillet, until reduced by about one-third, about 2 minutes. Add chicken stock; bring to a boil, and reduce heat to medium-low. Cook, stirring occasionally, until sauce is thickened, about 4 minutes.