Heat the oil in a small pan over medium heat, then add the chorizo and cook for 3–5 minutes until crisped at the edges and its spiced fat has fully rendered.
Use a slotted spoon to transfer the chorizo to a small bowl, leaving the rendered fat behind in the pan.
Add the diced onion to the chorizo fat with a tiny pinch of salt and cook for 3–4 minutes until softened and translucent.
Stir in the minced garlic, minced coriander stems, ground cumin, dried oregano, and smoked paprika, stirring constantly for 30–45 seconds until fragrant.
Pour in the black beans along with all of their canning liquid, and return the cooked chorizo to the pan.
Bring to a gentle simmer over medium-low heat for 8–10 minutes, stirring occasionally as the liquid thickens.
Using the back of a spoon or a potato masher, crush roughly one-third of the beans against the base of the pan to thicken the broth, stirring in stock or water if the mixture becomes too thick.
Remove the pan from the heat, stir through the fresh lime juice and chopped coriander leaves, and season with fine sea salt to taste.