Tenderize the chicken. Coat the pieces thoroughly with baking soda (about 1tsp per lb). Let the chicken sit for 10 minutes (no more than 15mins) at room temperature, then rinse it completely under cold water, pat it dry, and proceed to the next step.
In a large saucepan, heat olive oil over medium-high heat until shimmering.
Rinse the chicken and season with salt and pepper. Sear in your pan 2-4 mins on each side.
Add garlic, onion, carrots, and celery around the chicken. Cook, stirring occasionally, until the vegetables have softened, about 5 minutes.
Stir in the broth, tomatoes, chayote, zucchini, jalapeño, cumin, and coriander.
Bring to a boil; reduce heat and simmer, uncovered, for 20 minutes.
Remove the chicken and shred it.
Stir in chicken and cilantro (if using).
Season to taste (I like 1 teaspoon salt and ½ teaspoon pepper).
Serve, offering cheese, sour cream, avocado, and tortilla chips or your favorite toppings.
