Pour the dry beans into a strainer and rinse them under cold water. Then quickly sort through the beans and discard broken or damaged beans from the bowl.
Combine the black beans with the onion, garlic, salt, and two cups of water in the bowl of your Instant Pot.
Place the lid on the pot and seal the vent on top.
Set the Instant Pot to cook on high pressure for 1 hour and 20 minutes, or use the Beans setting on your pot.
When the cooking time is up, quickly release the pressure from the pot and remove the lid.
Transfer the bean mixture to a blender and add one cup of water. Blend until the soup is smooth.
Add the blended beans & chicken bouillon into a large pot and place on the cooktop. Bring the soup to a boil and cook for five to six minutes until heated through.
Remove the pan from heat, salt and pepper to taste. Then, serve immediately. Garnish with tortilla strips, avocado, grated cheese, sour cream and/or chili peppers, if desired.