Melt butter in large saucepan over medium
heat. Stir in flour until smooth; cook 1 minute, stirring
constantly. Stir in milk, beer, Worcestershire sauce, mustard,
salt, and pepper. Heat to a boil, stirring frequently. Reduce
heat; simmer 10 minutes, stirring frequently. Stir in cheese
until melted. Ladle soup into bowls. If desired, serve with
croutons. Serves 4.