- Preheat oven to 150˚C (300˚F).
- Place tortilla strips on a baking sheet and season with oil and salt.
- Place in the oven on the middle rack and bake about 30 minutes, turning them from time to time until crispy.
- Sauté the onion, garlic, and jalapeño pepper (if using) in oil in a saucepan.
- Add the tomatoes, broth, chili powder, and oregano. Bring to a boil and simmer, covered, for 10 minutes.
- Use a hand mixer to purée the soup.
- Add the black beans, sweet red pepper, and corn. Simmer, covered, for 10 minutes.
- To serve, spoon into bowls and top with tortillas.
For an original, savoury result, add different garnishes like fresh cilantro, grated cheddar, slices of avocado, lime wedges, sliced radish, green onions, hot peppers, and corn kernels.