Turn the Instant Pot on Sauté. When the panel reads HOT, add in the chorizo, onion, bell pepper, and garlic. Smash up the chorizo as much as you can. You do not need to cook it, you just want to break up the sausage as much as possible.
Pour in Rotel, beans, water, cumin, salt, and cilantro.
Close the lid. Cook at high pressure for 40 minutes. Allow pressure to release naturally for 10 minutes, and then release all remaining pressure.
Using the back of a wooden spoon, or using an immersion blender, roughly puree about half the beans to thicken the soup. Add additional water if needed.
Garnish as desired and serve.
Black Beans and Chorizo Soup Tips and Tricks
Sausage. Don't overcook the sausage. Remember the saute step, in the beginning, is just to break up the meat, not to cook it.
Substituting. You can sub Italian sausage for the chorizo if you prefer for a different taste. You can also use a different beans like red beans or kidney beans, dried lima beans etc. in this soup.
Mexican, not Spanish Chorizo. I made this with Mexican chorizo which is a fresh meat sausage, vs. Spanish Chorizo which is a smoked meat sausage. So really, any other fresh meat sausage will work--it will just taste different.
Soaking. Don't forget to soak the beans in hot water for an hour before cooking, or they won't cook properly.
Natural Release. Don't use a quick release (QPR) immediately when your soup is done cooking at high pressure. It needs the 10 minutes of Natural Pressure Release (NPR) to continue cooking, and to keep your soup from spewing through the valve.
Canned Beans. You can also make this with canned beans. Reduce water to 1 cup, and cook for 5 minutes under pressure, with 10 mins NPR.