
In a large saucepan, heat butter over medium heat. Add onion and celery; cook and stir 3-4 minutes or until onion is tender. Add potatoes, ham, chiles, parsley and pepper; cook and stir 1 minute.
Stir in broth; bring to a boil. Reduce heat; simmer, covered, 15-20 minutes or until potatoes are tender. Stir in corn, milk and cheese; heat through. If desired, serve with sour cream.