In a large dutch oven, heat oil, pepper, and onion over medium high heat for 5 minutes or until onion begins to soften and become translucent.
Add the garlic and sauté for another minute.
Add the broth, black beans, tomatoes, and red wine vinegar. Stir well.
Add the oregano, cumin, cayenne, salt and pepper. Allow soup to simmer for about 10 minutes.
Use an immersion blender to partially puree the soup, leaving some beans/vegetables whole. (You can also transfer 1/2 of the soup to a blender and puree it until smooth and then add back into the pot.) Bring to a simmer again for another 10-15 minutes or until soup has reached desired consistency.
Serve with sour cream, cilantro, jalapeño, avocado, etc.