In a 4-quart saucepan, bring chicken broth to a boil. Reduce heat; add the potatoes, carrots, celery, onion, salt and pepper. Cover and simmer for 12-15 minutes or until vegetables are tender., Meanwhile, melt butter in a medium saucepan; stir in flour until smooth. Gradually stir in milk. Bring to a boil over medium heat; cook and stir for 2 minutes or until thickened. Reduce heat. Add cheese, stirring until melted; add to broth along with chicken. Cook and stir until heated through.