01 - In a large mixing bowl, combine olive oil, lime juice, minced garlic, soy sauce, white vinegar, ground cumin, smoked paprika, dried oregano, chili powder, salt, and black pepper. Whisk until fully blended into a smooth, fragrant paste.
02 - Coat the chicken thoroughly with the marinade, working the mixture under the skin and into every crevice with your hands. Cover tightly and refrigerate for at least 2 hours, or ideally overnight for maximum flavor penetration.
03 - Preheat the oven to 425°F (220°C). Arrange the oven rack in the center position.
04 - Place the marinated chicken skin side up on a wire rack set over a roasting pan. Roast for 45 to 50 minutes, until the skin is deeply golden and crisp, and an instant-read thermometer inserted into the thickest part of the thigh registers 165°F (75°C).
05 - While the chicken roasts, combine mayonnaise, sour cream, jalapeños, cilantro, garlic, lime juice, olive oil, and salt in a blender or food processor. Blend on high until completely smooth and vibrant green. Transfer to a bowl, cover, and refrigerate until serving.
06 - Remove the chicken from the oven and let it rest for 10 minutes to allow the juices to redistribute. Carve into serving pieces and arrange on a platter. Serve with the chilled Aji Verde sauce on the side.