How to Make It
In a large saucepan or Dutch oven, combine the chicken broth and 1 cup water and bring to a boil. Add the chicken and corn and simmer until the chicken is cooked through, 10 to 12 minutes.
Remove the chicken and corn from the saucepan and reserve.
Strain the cooking liquid into a large bowl or measuring cup and reserve.
Wipe out the saucepan and heat the oil over medium heat. Add the onion, celery, and garlic and cook, stirring occasionally, until beginning to soften, 2 to 3 minutes. Add the potatoes and the reserved cooking liquid and bring to a boil. Reduce heat and simmer until the pota-toes are cooked through, 15 to 20 minutes.
Meanwhile, shred the chicken and cut the corn pieces into 1-inch-thick rounds. Return the chicken and corn to the soup. Add the lime juice, oregano, ½ teaspoon salt, and ¼ teaspoon pepper and cook until heated through, about 1 minute. Serve the soup with the avocado, cilantro, capers, and lime wedges