Make the broth: Add all of the ingredients for making the broth to a large heavy bottom pot. Place this over high heat and let it come to a boil. Then reduce the heat, cover the pot with a lid, and let it simmer for 30 to 45 minutes or until the chicken breasts are fully cooked.
Strain out the broth ingredients: Use a slotted spoon or a strainer to remove the solid ingredients from the pot. Discard the green onions, garlic, and cilantro stems. But save the chicken breast and set them aside to cool.
Cook the potatoes and corn: Add the guascas, corn, and sliced potatoes to the broth. Return the heat up back to high so that the liquid comes to a boil. Then reduce the heat to a simmer. Let this cook with the lid off for roughly 30 minutes or until the potatoes begin to break down and the broth is slightly thickened. If you want to you can smash some of the potatoes with the back of a wooden spoon to help break them down. Finally taste the broth and add salt and pepper to your liking. You will most likely need to add a good amount of salt as the potatoes really need it!
Shred the chicken: Remove the meat of the chicken from the bone and discard the bone. Then use either your hands or two forks to shred the chicken meat. If you want you can add the chicken meat back to the soup, but It’s often traditional to serve it on the side so people can add as much as they want.
Serve: Place the capers, cilantro, sour cream, and aji picante into individual bowls. Have the shredded chicken meat on an individual plate. Then let everyone pour themselves individual bowls of the soup including potatoes & corn. And finally, let everyone add as much chicken & garnishes as they prefer.
Enjoy!