Heat avocado oil in a large heavy-bottomed pot over medium heat and sauté onion, bell pepper, and jalapeno until softened, approximately 5 minutes.
Add minced garlic, cumin, chili powder, smoked paprika, salt, and pepper; cook for 1 minute until fragrant.
Pour in the chicken bone broth, fire-roasted tomatoes (with liquid), and green chiles.
Add the whole chicken breasts to the liquid and bring to a gentle boil, then reduce heat to medium-low and simmer for 20-25 minutes until the chicken is fully cooked.
Remove the chicken from the pot and use two forks to shred it into bite-sized pieces.
Return the shredded chicken to the pot along with fresh cilantro and lime juice, stirring to combine and heating through for an additional 2 minutes.
Ladle the soup into bowls and garnish with avocado slices, shredded cheese, and crisped keto tortilla strips.