Brown ground beef in skillet and drain. Set aside.
Spray large pot with nonstick cooking spray and heat over medium heat. Add the onion, green pepper, diced tomatoes, and whole tomatoes. Add cumin and chili powder, to taste, and cook for about 8 minutes or until vegetables are tender.
Add the beans, the ground beef, chili seasoning and chopped celery. Let simmer and slow cook for 4 hours.
Serve with Cheddar cheese, sour cream, and green onion as garnishes.