Meanwhile, in a small skillet, melt remaining butter. Add flour; cook and stir until bubbly, 3-5 minutes. Add to soup; bring to a boil. Cook and stir 2 minutes. Reduce heat to low. Stir in cheese, milk, salt and pepper; cook until cheese melts. Remove from heat; blend in sour cream. Yield: 8 servings (2-1/4 quarts).