Coat a large saucepan with cooking spray and cook 1 chopped sweet onion over medium heat until tender, about 5 minutes. Add chili starter, oregano, and chicken broth; increase heat to medium-high and simmer for 20 minutes.
Coat a large stock pot with cooking spay and cook remaining 1/2 chopped sweet onion, green bell pepper, and jalapeno pepper over medium heat until tender, 5 to 8 minutes. Add ground cumin, cocoa powder, chili powder, garlic salt, paprika, and cayenne pepper; cook 2 minutes. Mix in ground turkey and pork; cook and stir until meat is crumbly, evenly browned, and no longer pink, about 10 more minutes. Drain and discard any excess grease.
Stir diced tomatoes with green chiles, fire-roasted tomatoes, and diced tomatoes with green peppers and onions into chili; simmer for about 3 hours.