Heat the olive oil in a large pot over medium heat.

Add the onion, carrot, celery, and bell pepper. Cook about 5–7 minutes until vegetables begin to soften.

Stir in the minced garlic and cook for another 30 seconds until fragrant.

Pour in the chicken broth and the canned diced tomatoes (with their liquid). Stir to combine.

Add the chicken breasts, ground cumin, salt, and black pepper. Bring the soup to a gentle boil.

Reduce heat to a simmer, cover, and cook for 20 minutes, or until the chicken is cooked through and vegetables are tender.

Remove the chicken from the pot and shred it with two forks. Return the shredded meat to the soup and stir to combine.

Taste and adjust seasoning if needed. If you like, stir in chopped fresh cilantro.

Serve hot, topped with avocado slices, a squeeze of lime, and optionally a spoonful of sour cream or yogurt.