Heat the olive oil in a large pot over medium heat. Add the onion, garlic, and jalapeño and cook for 4 to 5 minutes until the onion softens.
Stir in the cumin and oregano and cook for 30 seconds until fragrant.
Pour in the chicken broth and add the drained tomatoes and chicken breasts. Bring the mixture to a simmer.
Cook for 15 to 18 minutes until the chicken reaches an internal temperature of 165°F.
Remove the chicken from the pot, shred it with two forks, and return it to the broth.
Stir in the lime juice and cilantro. Season with salt and black pepper.
Ladle the soup into bowls and top each serving with avocado slices and lime wedges.