In a Dutch oven or large stock pot, saute the mushrooms, onion, celery, carrot and corn in butter until tender. Stir in flour until blended. Add the broth and seasonings; mix well. Bring to a boil. Reduce heat; simmer, uncovered, for 10 minutes.
Stir in the cream, chicken, parsley, lemon juice and salt; heat through (do not boil). Yield: 11 servings (2-3/4 quarts).