Add beef to a large saucepan and cook on medium heat.
Add onions and bell peppers. Cook until onions are translucent and soft.
Add garlic, cayenne pepper, cumin, paprika, and oregano. Stir until fragrant (about 1 minute).
Add meat back to pan with salt, pepper, diced tomatoes, chicken broth, and bay leaves.
Bring contents of the pan to an aggressive simmer, and simmer uncovered for 1 hour, 45 minutes to 2 hours — or until the sauce is thick (see note below).