Puree 2 cans of black beans, diced tomatoes, and 1 can of vegetable broth.

Transfer the pureed mixture to a large soup pot (at least 6 quarts).

Add the remaining 2 cans of black beans, 2 cans of vegetable broth, chopped onion, chopped carrots, chopped celery, chopped garlic, chopped mushrooms, chili powder, ground cumin, black pepper, and frozen corn to the pot.

Bring the soup to a boil, stirring frequently to prevent sticking and burning.

Reduce the heat to low and simmer for 30 minutes, stirring occasionally.