Prepare the Marinade: In a medium bowl, whisk together all the marinade ingredients: minced garlic, soy sauce, vegetable oil, lime juice, cumin, smoked paprika, oregano, black pepper, and salt. Mix until everything is well combined.

Spatchcock the Chicken: Place the chicken breast-side down on a cutting board. Using a sturdy pair of kitchen shears, cut along both sides of the backbone to remove it completely. You can save the backbone for making stock. Flip the chicken over and press down firmly on the breastbone to flatten it. This technique is explained well on Serious Eats and helps the chicken cook much more evenly.

Marinate the Chicken: Pat the chicken skin dry with paper towels. Place the chicken in a large dish or a sealable plastic bag. Pour the marinade all over the chicken, making sure to rub it under the skin and into every crevice. I find that using my hands is the best way to ensure it's fully coated. Cover and refrigerate for at least 4 hours, or ideally overnight for the best flavour.

Preheat and Prepare for Roasting: When you're ready to cook, take the chicken out of the fridge 30 minutes before roasting to allow it to come to room temperature. Preheat your oven to 200°C (180°C fan). Place the chicken, skin-side up, on a rack set inside a roasting tin. Discard any excess marinade.

Roast the Chicken: Roast for 1 hour to 1 hour and 15 minutes. The chicken is cooked when the juices run clear when a thigh is pierced with a skewer, and a meat thermometer inserted into the thickest part of the thigh reads 74°C. The skin should be deep golden brown and crisp.

Make the Aji Verde Sauce: While the chicken is roasting, prepare the green sauce. Add all the Aji Verde ingredients—coriander, jalapeños, garlic, mayonnaise, feta cheese, lime juice, olive oil, and salt—to a high-speed blender. Blend on high until the sauce is completely smooth and creamy. It should be a beautiful, vibrant green. Taste and adjust seasoning if needed.

Rest and Serve: Once the chicken is cooked, remove it from the oven and let it rest on a cutting board for at least 10-15 minutes before carving. This is crucial for keeping the meat juicy. Carve the chicken and serve immediately with a generous amount of the fresh Aji Verde sauce on the side.