In a large saucepan, saute the onion, celery and red pepper in butter until vegetables are crisp-tender.
Stir in flour and dressing mix until smooth; gradually stir in milk. Bring to a boil; cook and stir for 2 minutes or until thickened.
Add the potatoes, corn, and ham. Bring to a boil. Reduce heat; simmer, uncovered, for 8-10 minutes or until heated through. Sprinkle with cheese before serving. Yield: 8 servings (2 quarts).