Sauté veggies: Heat olive oil in a large pot over medium heat. Add chopped onion and bell pepper. Cook 3–4 minutes until softened. Add garlic for the last 30 seconds.
Brown the meat: Add ground beef or turkey. Cook until browned, breaking it apart with a spatula. Drain excess fat if necessary.
Add spices: Sprinkle in chili powder, cumin, paprika, cayenne, and salt. Stir for 1–2 minutes until fragrant.
Combine beans & tomatoes: Add kidney beans, black beans, and diced tomatoes. Stir well. Simmer on low-medium heat for 15–20 minutes, stirring occasionally.
Taste & adjust: Check seasoning. Add more salt or cayenne pepper if needed.
Serve: Spoon into bowls and top with cheese, sour cream, cilantro, or crushed chips.