In a large (5- to 6-quart) soup pot, cook the chorizo over medium heat, stirring to break up any clumps, until it’s crispy, about 10 minutes. With a slotted spoon, scoop the chorizo onto a paper towel to drain, leaving behind as much fat as possible.
Scoop the leeks and chiles into the pot, cover and return to medium heat. Let cook, uncovering to stir from time to time, until the leeks and chiles are very soft, about 10 minutes. Uncover and continue to cook, stirring frequently, until the leeks and chiles look thoroughly melted and are just beginning to brown, about 10 minutes more. Scrape the leek mixture into a blender jar, add 1 can (or 1 ¾ cup) of the beans and the chicken broth. Blend until smooth and return to the pan.
Add the remaining can of beans to the soup and bring to a simmer over medium heat. Taste and season with salt, usually a scant teaspoon depending on the saltiness of your broth and beans. Let simmer for a few more minutes to blend the flavors, then ladle into warm soup bowls, sprinkle with the crispy chorizo and garnish with the herb leaves, cheese or crema—whatever you have. Soup’s on.