If using a whole chicken, pat it dry with paper towels. To spatchcock, flip the chicken breast-side down, use kitchen shears to cut out the backbone, then press firmly on the breastbone to flatten. Tuck wing tips under. Leave skin on for best results.

Make the marinade

In a blender or food processor, combine garlic, lime juice, vinegar, soy sauce, aji amarillo paste, paprika, cumin, oregano, black pepper, kosher salt, and vegetable oil. Blend until a smooth paste forms. If mixture is too thick, add 1–2 tbs water or a splash of the beer/stock to loosen.

Marinate the chicken

Place the chicken in a large zip-top bag or shallow dish. Pour the marinade over the chicken, making sure to rub some under the skin over the breasts and thighs. Reserve 1/4 cup of the marinade (not the raw juices) in a small bowl for basting. Seal the bag or cover and refrigerate for at least 6 hours, ideally overnight (8–24 hours) for best flavor.

Cook

Preheat

Remove the chicken from the refrigerator 30–45 minutes before cooking to come closer to room temperature. Preheat oven to 425°F (220°C) if roasting. If using a grill, set up for indirect heat with a medium-high zone (about 400–450°F / 200–230°C) and a cooler zone for indirect cooking.

Roast or grill the chicken

If roasting: place the spatchcocked chicken skin-side up on a wire rack set in a rimmed baking sheet. Roast in the preheated oven for 35–50 minutes, depending on size, until skin is deep golden-brown and an instant-read thermometer inserted into the thickest part of the thigh (without touching bone) reads 165°F (74°C). If grilling: place the chicken skin-side down over direct heat for 6–8 minutes to crisp and brown the skin, then move to the cooler zone skin-side up and cook with the lid closed for 20–35 minutes until internal temp reaches 165°F (74°C).

Baste for color and moisture

Every 10–15 minutes during cooking (after the initial sear on the grill or after the first 15 minutes in the oven), brush the reserved 1/4 cup marinade mixed with the optional beer or stock over the skin to enhance browning and flavor. Discard any leftover marinade that has contacted raw chicken.

Rest the chicken

When the chicken reaches 165°F (74°C), remove from oven or grill and tent loosely with foil. Let rest 10–15 minutes to allow juices to redistribute.

Serving & Garnish

Transfer the chicken to a cutting board. Carve into portions: remove legs and thighs, then wings, and slice breast meat. Sprinkle chopped cilantro or parsley over the top and serve with lime wedges and aji verde on the side. Traditionally serve with French fries or roasted potatoes.