Heat 1.5 tablespoons of olive oil in a large pot over medium-high heat. Add in onions, garlic and tomatoes. Cook until onions become translucent, about 3 minutes. Add salt, black pepper, oregano, thyme, cumin and red pepper flakes. Stir and cook for another 4 minutes until very fragrant. Add in vegetable broth, black beans and stir. Cover and cook for 15 minutes. The soup will be boiling by the end. Uncover and with a hand held immersion blender, blend a few times until the soup reaches your desired consistency. Cook uncovered for another 15 minutes. Stir and serve. Top with diced avocados, diced tomatoes, a dollop of sour cream or Greek yogurt, cilantro and lime wedges.