Step 1

Place the chicken, onion, garlic, salt, and pepper in a baking dish and toss to combine. Cover and refrigerate for 8 to 24 hours.

Step 2

Heat the olive oil in a heavy 4-quart lidded pot, like the Chambaware pot or a Dutch oven, over medium-high heat until shimmering. Add the chicken with its marinating bits and brown each side, about 6 minutes total. Pour in the broth and raise the heat to high. When the mixture boils, lower the heat to medium-low, then cover and simmer until the chicken is tender, about 30 minutes.

Step 3

Transfer the chicken to a platter, reserving the cooking liquid in the pot. When cool enough to handle, remove the skin from the chicken and discard. Cut or tear the chicken breasts into bite-size strips and discard the bones.

Step 4

Place the potatoes in the pot with the leftover cooking liquid and set over medium heat. Cover and cook for about 5 minutes.

Step 5

Add the corn, the bunch of scallions, the bunch of cilantro, and the guascas. Simmer with the lid on for 20 minutes, or until potatoes are tender but not overcooked. Remove the cilantro and scallions and return the shredded chicken to the pot. Simmer another few minutes until the chicken is warmed through. Ladle the soup into individual bowls and place the toppings on the table to be passed around.