Make the peri peri marinade. In a blender or food processor, combine the bird's eye chillies, garlic, red bell pepper, smoked paprika, oregano, cumin, salt, black pepper, lemon juice, white wine vinegar, olive oil, and tomato paste. Blitz until you have a smooth, vibrant red sauce — it should be thick but pourable, with a sharp, spicy aroma that makes your eyes water slightly.

Prepare the chicken. Pat the chicken thighs dry with kitchen paper. Using a sharp knife, make 2-3 deep slashes into the flesh of each thigh, cutting down to the bone. This allows the marinade to penetrate deeply and helps the fat render during grilling.

Marinate the chicken. Place the chicken in a large bowl or a resealable bag. Pour over the peri peri sauce, using your hands to massage it into every crevice and under the skin. The chicken should be completely coated — you'll see a rich orange-red layer clinging to the skin. Cover and refrigerate for at least 2 hours, but 4 hours is better. Overnight gives you the most intense flavour.

Bring to room temperature. About 30 minutes before grilling, remove the chicken from the fridge. This step is crucial — cold meat cooks unevenly and can dry out on the outside before the inside is done. You'll feel the chicken lose its fridge chill.

Preheat your grill. Heat your grill or grill pan to medium-high heat (about 200°C / 400°F). You want it hot enough to sear, but not so hot that the sugar in the marinade burns. If using a charcoal grill, wait until the coals are covered with a light grey ash and there's a steady, medium heat.

Grill the chicken. Place the chicken thighs skin-side down on the grill. You should hear a satisfying sizzle immediately. Cook for 6-8 minutes without moving them — this creates those deep, dark grill marks. The skin will start to crisp and pull away from the grate easily when it's ready to flip. Turn the chicken over and cook for another 6-8 minutes. The aroma of smoked paprika and charring chillies will fill your kitchen.

Check for doneness. Use a meat thermometer inserted into the thickest part of a thigh (avoiding the bone). The internal temperature should read 74°C (165°F). If you don't have a thermometer, pierce the thickest part with a knife — the juices should run clear, not pink, and the meat should feel firm to the touch.

Rest and serve. Transfer the grilled chicken to a warm plate, tent loosely with foil, and let it rest for 5 minutes. This allows the juices to redistribute throughout the meat. When you cut into it, you'll see the meat is beautifully moist, with a dark, caramelised skin that's slightly sticky from the marinade. Garnish with fresh coriander if using.