Cook on high setting for approximately 6 hours, or until the beans are soft and cooked through (or, cook on low for 8-10 hours). It's important to know your slow cooker. Each slow cooker cooks differently. Adjust cooking times and temperatures accordingly.
Using a hand blender, blend the soup right in the crock pot until you achieve the texture and smoothness you prefer. If you don't have a hand blender, cool the soup for a bit and then transfer a few cups at a time into a blender or food processor and blend till smooth.
Season with salt and pepper and garnish with fresh cilantro if desired.
Instant Pot Instructions
If you prefer to cook this faster with an IP, the only thing that changes is the settings. Set at high pressure, press the manual button and adjust cooking time to 35 minutes. Make sure the lid is secure and the vent is closed. When done cooking, blend as instructed above.
Stovetop Instructions
While this recipe is MUCH easier to make in a slow cooker or Instant Pot, it can also be made on the stove top if you don't have one of the other two appliances. The difference is in the cooking time. It can take a good long while for dry beans to cook. The important thing is to keep a lid on them so that the liquid doesn't evaporate too much during cooking. Keep an eye on this just in case you need to add more broth. This recipe was formulated for a slow cooker, but it can absolutely be made on the stove top if you have the time and patience.
Notes
Please note that the nutrition data below is a ballpark figure. Exact data is not possible.