In a large pot over medium heat, soften the onions and garlic in the oil. Add the bell peppers and chili powder. Cook for 1 minute, stirring constantly. Add the remaining ingredients. Season with salt and pepper.
Bring to a boil. Simmer over medium heat for 30 minutes, stirring often. Add water, as needed, if the chilli is too thick.
Serve with the sour cream and garnish with cilantro.
Beans cooked without salt added can be easily found in the canned vegetable section of your grocery store.