01 - In a large bowl, whisk together the olive oil, soy sauce, lime juice, minced garlic, ground cumin, smoked paprika, dried oregano, black pepper, salt, and chili powder until well combined.
02 - Pat the butterflied chicken dry with paper towels. Rub the marinade thoroughly over and under the skin, ensuring even coverage. Cover tightly and refrigerate for at least 2 hours, preferably overnight for deeper flavor penetration.
03 - Preheat the oven to 425°F. Line a baking tray with aluminum foil and set a roasting rack on top. Place the chicken skin-side up on the rack.
04 - Roast for 45 to 55 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. Remove from the oven and let the chicken rest for 10 minutes before carving to allow the juices to redistribute.
05 - While the chicken rests, combine the fresh cilantro, seeded jalapeño or serrano chile, garlic cloves, mayonnaise, sour cream, lime juice, grated parmesan, and olive oil in a blender or food processor. Blend until completely smooth. Season with salt and pepper to taste.
06 - Carve the rested chicken into serving pieces. Arrange on a platter and drizzle generously with the aji verde sauce. Serve alongside roasted potatoes or a simple salad for an authentic Peruvian meal.