Warm 1 tablespoon olive oil in a large stock pot or Dutch oven over medium-low heat. Then add all of the remaining Soup ingredients (carrots through corn tortillas) and bring to a boil. Once boiling, immediately reduce heat to low and let simmer partially covered for 20-30 minutes until the vegetables and tortillas soften. Stir occasionally.
Meanwhile, pile the black beans at the center of a large rimmed baking sheet and top with 1 tablespoon olive oil and 1/2 teaspoon salt. Gently toss the beans with your hands and then spread them in an even layer across the baking sheet. Put in a pre-heated 425° oven for 15-20 minutes or until the beans split and become crispy. Once done, remove the pan from the oven and set aside.
After the soup ingredients have softened, work in batches to purée the soup in a blender or use an immersion blender directly into the pot. Blend until smooth throughout. Keep the puréed soup warm over low heat until ready to serve.
Portion the soup into serving bowls and top each bowl with a few dollops of yogurt, Mexican crema, or sour cream. Drag your spoon through the dollops to create a swirl pattern. Add a small mound of toasted black beans to the center of each bowl. Serve any remaining beans on the side. See TIP B for make-ahead and freeze instructions.
TIP A: For this recipe, you want to be sure to use 100% white or yellow corn tortillas (not wheat or flour blend), and typically the less fat content, the better. Corn tortillas with too much added fat do not break-down as easily in the soup.
TIP B: This is a great soup to make-ahead and freeze for a rainy day. After you purée the ingredients, transfer the soup to an air-tight container and freeze for up to 3 weeks. When ready to serve, defrost and re-heat slowly over a low flame. Toast the beans as the soup re-heats.