In a saucepan, brown the onion and celery in the butter. Add the chicken and sauté until golden brown. Add the garlic and cook for 1 minute. Sprinkle with the flour and cook for 1 minute, stirring constantly. Add the broth, potatoes, and cream. Bring to a boil, stirring continuously. Simmer gently for about 15 minutes or until the potatoes are tender. Add the corn and cook 5 minutes. Add the parsley and adjust the seasoning.