In a blender or food processor, combine the bird's eye chilies, garlic, olive oil, red wine vinegar, smoked paprika, lemon juice, and kosher salt. Blend for about 1 minute until it forms a smooth, vibrant red paste.

Place the butterflied chicken in a large dish and rub the piri-piri paste all over, ensuring you get it underneath the skin as well. For best flavor, cover and let it marinate in the refrigerator for at least 2 hours, or overnight if possible.

Preheat your grill to medium-high heat (about 400°F). Lightly oil the grates using a paper towel dipped in oil to prevent the chicken from sticking.

Place the chicken skin-side down on the grill and cook for 15-20 minutes, allowing the skin to become deeply charred and crispy. Flip the chicken and cook for another 15-20 minutes until the internal temperature reaches 165°F in the thickest part of the thigh.

While the chicken is grilling, prepare the slaw by tossing the shredded cabbage and julienned carrots in a large mixing bowl. In a small separate bowl, whisk together the mayonnaise, apple cider vinegar, honey, and black pepper.

Pour the dressing over the cabbage mixture and toss well until all the vegetables are evenly coated. Let the slaw sit for 10 minutes to allow the flavors to meld and the cabbage to soften slightly.

Remove the cooked chicken from the grill and let it rest on a cutting board for 10 minutes to lock in the juices. Carve the chicken into portions and serve alongside a generous scoop of the cooling slaw, garnished with extra lemon wedges if desired.