Black Bean Chili

1 pound black beans or 4 cans black beans, drained
2 cups tomatoes, puréed
2 to 3 cups vegetable broth, water or chicken broth
1 onion, chopped
1 teaspoon garlic, minced
2 teaspoons chili powder
1 teaspoon dried leaf oregano
1/2 teaspoon cumin
1/2 teaspoon salt, or to taste
Freshly-ground pepper, to taste

If using dried beans, clean and soak beans overnight, then drain. Cover with fresh water and cook until tender, about 2 hours. Drain.