Sauté onion, celery, green pepper, and bacon in a large saucepan. Add chicken stock, salt, pepper, parsley, and thyme. Peel and dice potatoes, then add to the saucepan. Add corn, and simmer for 30 minutes. In a separate pan, melt butter and stir in flour. Add the half & half and whip until smooth. Add to the soup, and cook 10 minutes to blend.