Heat the oil in a large pot over medium-high heat. Add the onion, bell pepper, and garlic. Cook stirring frequently until tender, about 5 minutes. Add the turkey and cook until no longer pink, breaking up and chunks with the back of a spoon. Add the chili powder, cumin, oregano, salt, cayenne, and black pepper. Cook for 1 minute, stirring constantly

Stir in the tomatoes, beans, broth, and brown sugar, scraping the bottom of the pot to loosen any stuck-on or browned bits. Bring to a boil.
Reduce the heat to medium-low, and simmer, uncovered, until the chili thickens, about 45 minutes. Serve topped with shredded cheese, sour cream, and sliced green onions.