In a large pot, heat olive oil over medium heat. Add the chopped onion, and cook until translucent, about 5 minutes.
Add the minced garlic and chopped bell pepper to the pot and cook for another 3-4 minutes, until the bell pepper softens.
Stir in the black beans, vegetable broth, diced tomatoes, cumin, chili powder, and smoked paprika. Bring to a simmer and let cook for 20 minutes.
After 20 minutes, use a blender or immersion blender to puree the soup to your desired consistency. If you prefer a chunkier soup, blend only half of it or use a potato masher.
Season with salt and pepper to taste. Let the soup simmer for an additional 5 minutes.
Serve hot, garnished with fresh cilantro, avocado slices, and lime wedges on the side.