Sauté the vegetables. Heat 2 tablespoons of olive oil in a large Dutch oven or heavy-bottomed soup pot over medium heat. Add the diced onion and jalapeño and sauté for 4-5 minutes, stirring occasionally, until softened.
2 tablespoons olive oil, 1 medium yellow onion, 1 jalapeño
Add the garlic and spices. Stir in the minced garlic and cook for approximately 30 seconds. Add the ground cumin, chipotle chili powder, Mexican oregano, salt, and black pepper. Stir continuously for another 30 seconds to release their flavors.
5 cloves garlic, 1½ teaspoons ground cumin, 1 teaspoon dried Mexican oregano, 1 teaspoon salt, ½ teaspoon freshly ground black pepper, 1 teaspoon chipotle chili powder
Cook the tomato paste. Add the tomato paste and mix thoroughly with the vegetables and spices. Continue cooking for 1 minute, stirring frequently to prevent burning.
1 tablespoon tomato paste
Prepare the broth. Stir in the fire-roasted diced tomatoes, including their juices, followed by the chicken stock. Scrape the bottom of the pot to release any browned bits and combine everything thoroughly.
2 (14.5 ounce) cans fire roasted diced tomatoes, 6 cups low-sodium chicken broth
Simmer the chicken. Place the chicken thighs in the broth; bring the soup to a gentle boil, then reduce the heat to low. Cover and simmer for 20-25 minutes, adjusting the heat as necessary to maintain a gentle simmer, until the chicken reaches an internal temperature of 165°F. Prepare the crispy tortilla strips while the chicken cooks (see instructions below).
1½ pounds boneless skinless chicken thighs
Shred the chicken. Remove the cooked chicken from the Dutch oven and transfer it to a plate or cutting board. Allow it to cool slightly, then shred into bite-sized pieces using two forks.
Add the corn and beans. Stir the corn kernels and drained, rinsed black beans into the simmering broth. Cook for approximately 5 minutes, stirring occasionally, until heated through.
1 cup corn kernels, 1 (14.5 ounce) can black beans
Finish the soup. Return the shredded chicken to the pot and stir to combine. Reduce the heat to low, then add the fresh lime juice and chopped cilantro. Taste and adjust the salt, pepper, and lime juice as needed.
1 tablespoon fresh lime juice, ¼ cup chopped fresh cilantro
To serve. Ladle the hot chicken tortilla soup into bowls. Top with crispy baked tortilla strips, diced avocado, fresh cilantro, and lime wedges. Add crumbled Cotija or queso fresco and sour cream, if desired. Serve immediately.
avocado, lime wedges, fresh cilantro, crumbled Cotija or queso fresco, and sour cream