Preheat oven to 400 ?F. For croutons, butter both sides of bread. Place on baking sheet and sprinkle with Italian seasoning. Bake until lightly browned, about 12 minutes, turn slices over and bake until browned, about 12 minutes longer. Cool; cut into cubes. Meanwhile, for soup, melt butter in a large Dutch oven. Saut? celery and onion until tender, about 10 minutes. Stir in flour and seasonings until smooth. Gradually add milk, broth and Worcestershire sauce. Bring to boiling, stirring constantly. Boil and stir 1 minute. Reduce heat to low. Gradually stir in cheese, stirring until cheese is melted after each addition. Serve with croutons.