Add the onion, bell pepper and celery and cook 5 minutes more, stirring occasionally. Add the garlic, chili seasoning and a pinch of salt. Stir to combine and cook for one more minute. Add the green chiles, sweet potatoes, tomato sauce, tomato paste, beef broth, water, beans and corn. Stir, then bring to simmer. Simmer, covered, for 20 minutes, stirring occasionally.