Stir in spices and mix well, cooking until fragrant and spices are lightly toasted.
1 teaspoon ground cumin, 1 teaspoon ground coriander, 1 teaspoon epazote, 1 teaspoon fine sea salt
Add beans and vegetable broth. Bring the mixture to a boil, then reduce heat to a simmer. Cover and cook for 20 minutes.
3 cups cooked black beans, 4 cups vegetable broth
Remove half the soup and puree in a blender or food processor, then return to the pot and stir well. Simmer another 5 minutes and serve with your favorite toppings.
Notes
If using dried beans, soak 1/3 cup overnight, then cover with water in a saucepan. Bring to a boil, then let simmer until tender, 45-90 minutes.
You can also use an immersion blender to puree the soup, stopping once about half of the soup is blended.