3 pounds chicken, bone-in thighs and drumsticks – patted dry
2.5 tsp kosher salt – divided
1 tsp ground black pepper
2 cups yellow onion – finely chopped
5 cloves garlic – minced
2 tsp ground cumin
1 tsp dried oregano – crumbled
2 tbsp tomato paste
2 each bay leaves
1 cup pale lager beer
1 tbsp white vinegar
2 each scallion – thinly sliced (for serving)
0.25 cup flat-leaf parsley – chopped (for serving)
Instructions
Cover the rinsed chuño with half of the measured water (about 1.5 quarts) in a medium pot, stir in 0.5 tsp of the kosher salt, and soak 20 minutes.
Bring the same pot to a boil and cook the chuño until tender, 25–30 minutes; drain and keep warm.
Place the peeled potatoes in a second pot with the remaining 1.5 quarts water and 1 tsp kosher salt; bring to a boil and cook until just tender when pierced, 20–25 minutes. Drain and keep warm.
Cook the long-grain white rice according to package directions and keep warm for serving.
Toast the dried ajà panca chiles in a dry skillet over medium heat until fragrant and pliable, 1–2 minutes per side. Transfer to a bowl and pour 1 cup of the hot chicken stock over them; soak 15–20 minutes, then blend until completely smooth.
Heat the vegetable oil in a wide heavy pot over medium-high heat. Season the chicken with 0.75 tsp kosher salt and 0.5 tsp black pepper, then brown in batches until golden, 3–4 minutes per side. Transfer to a plate.
Reduce heat to medium. Add the chopped onion to the pot and cook, stirring, until translucent and lightly golden, 6–8 minutes. Stir in the minced garlic, ground cumin, and dried oregano; cook 1 minute until aromatic, then add the tomato paste and cook 2 minutes.
Stir in the blended chile paste and cook, stirring, until thickened and brick red, 2–3 minutes.
Pour in the pale lager beer and simmer, scraping up browned bits, 2–3 minutes.
Return the browned chicken and any juices to the pot. Add the remaining 3 cups chicken stock and the bay leaves. Bring to a simmer, cover, and cook 20 minutes; uncover and continue simmering until the chicken is tender (165°F in the thickest part) and the sauce coats a spoon, 10–15 minutes. Stir in the remaining 0.25 tsp kosher salt and the remaining 0.5 tsp black pepper.
Off the heat, stir in the white vinegar.
Serve the chicken and its sauce with the boiled potatoes, chuño, and cooked rice. Garnish with the sliced scallions and chopped parsley.