Heat olive oil in a large pot and add in onions, pepper, carrots, and celery. Season with salt and pepper and cook for 8-10 minutes or until the veggies begin to look tender.
While veggies are cooking, blend cilantro, Serrano pepper, 1 clove garlic and 2 cups of broth in the blender. Set aside.
Once veggies are tender, season with cumin, oregano, and a little more salt and pepper, stir well and cook for another 2 minutes.
Add shredded chicken, zucchini, corn, remaining chicken broth and the cilantro broth you blended in the blender. Bring to a boil, reduce down and simmer for 10 more minutes or until your veggies are tender.
Finish with a few handfuls of baby spinach and enjoy!