In a large pot, place the chicken, corn, chicken bouillon, cilantro, scallions, garlic, salt and pepper. Add the water and bring to a boil, then reduce heat to medium and cook for about 35 to 40 minutes, until chicken is cooked and tender. Remove the chicken and set aside.
Continue cooking the corn for 30 more minutes. Discard green onion and add red potatoes, white potatoes, and the guascas. Cook for 30 more minutes.
Uncover and add the frozen papa criolla and simmer for 15 to 20 minutes, season with salt and pepper.
Cut the chicken meat into small pieces and return to the pot. Serve the Ajiaco hot with capers and heavy cream on the side.