In a large saucepan over medium heat, sauté the onions.
Once the onions are translucent, add the garlic, bell pepper, and green chilis. Cook for another 5 minutes.
Add the ground beef to the pan and cook until browned.
Add the diced tomatoes, tomato paste, Worcestershire sauce, chili powder, cumin, Italian seasoning, bay leaf, salt, and pepper.
Stir until well-combined.
Bring the ingredients to a simmer and cook for 30 minutes to 1 hour. If the mixture appears dry, add a splash of beef broth.