Heat olive oil in a large pot over medium-high heat. Add diced red onion and jalapeño, cooking for 3-4 minutes until translucent. Stir in minced garlic and sauté for 30 seconds until fragrant.

Add chicken breasts, fire-roasted corn, and diced green chiles to the pot. Sprinkle with Tajín, cumin, chili powder, salt, and pepper. Stir to combine.

Pour in chicken stock, bring to a boil, then reduce heat and simmer for 25 minutes.

Remove chicken, shred it, and return it to the pot.

Stir in sour cream and shredded cheese, simmering for 3 minutes until melted and creamy.

Ladle into bowls, garnish with queso fresco and cilantro, and serve with lime wedges.