Heat the oil in a Dutch oven over medium-high heat and brown the beef in two batches until it reaches 160°F.
Drain excess fat, return all the beef to the pot and mash it into very small even crumbles with a potato masher.
Add the onion and bell pepper and cook for 6 minutes until soft, then stir in the garlic for 30 seconds.
Add the tomatoes, tomato sauce, broth, chili powder, cumin, salt and black pepper and bring to a gentle simmer.
Cook uncovered over low heat for 60 minutes, stirring and breaking up any larger beef pieces.
Add the kidney and pinto beans and simmer for 25 to 30 minutes until the broth coats the spoon.