In a large pot or Dutch oven, heat 1 tablespoon of olive oil over medium-high heat. Add the diced red onion and jalapeño, cooking for 3-4 minutes until the onion is translucent. Stir in the minced garlic and sauté for an additional 30 seconds.
Add the boneless, skinless chicken breasts, fire-roasted corn, and diced green chiles. Sprinkle in the Tajín seasoning, ground cumin, chili powder, salt, and black pepper. Stir well to coat evenly.
Pour in 4 cups of chicken stock and bring to a boil. Once bubbling, reduce heat to a simmer, cover, and cook for 25 minutes until chicken is cooked through.
Carefully remove the chicken breasts, shred them into bite-sized pieces, and return to the pot. Stir the shredded chicken into the soup.
Lower the heat and stir in ½ cup of sour cream or Greek yogurt, 1 cup of shredded Monterey Jack cheese, and the juice of 1 lime. Mix until well combined and creamy; let it simmer for another 3 minutes.
Ladle the soup into bowls, garnishing with crumbled queso fresco and chopped fresh cilantro.
Notes
For best flavor, use fresh ingredients and adjust the spice level according to preference. This soup freezes well for future meals.