Heat a large pot over medium-high heat.
Add the ground beef or turkey and cook until browned.
Once the meat is cooked, add the onions, bell peppers, and garlic.
Cook for 5 minutes, stirring occasionally.
Add the chili powder, cumin, oregano, salt, black pepper, and red pepper flakes.
Stir to combine and cook for an additional 2 minutes.
Add the black beans, kidney beans, and beef broth.
Bring to a boil, then reduce the heat to low.
Simmer for 20 minutes, stirring occasionally.
Taste and adjust seasoning if necessary.
Serve with your favorite toppings.