Pick through the beans and discard any debris. In a food processor, add garlic, onion, red bell pepper, green pepper, and scallion.
Cook the chorizo in the oil in a large pot over medium heat, stirring occasionally, about 5 minutes. Using a slotted spoon, transfer the chorizo to a plate lined with paper towels.
In a large pot over medium heat, add the beans, 6 cups of water, beef broth, processed vegetables, and carrots. Slightly cover and simmer for 1 1/2 hours.
Add the chorizo, ground cumin, cilantro, and potatoes. Simmer for 30 to 40 minutes or until the beans are tender.
Season with salt and pepper. Serve with white rice and avocado on the side.