Preheat oven to 200°C. Use a sharp pair of scissors to remove the chicken’s backbone, then pat dry inside and out with kitchen paper. Season generously with salt and pepper.
Combine the marmalade, lime juice, macadamia oil, garlic and turmeric in a blender, then purée until very smooth. Load half the mixture into a meat injector and inject into the breasts and thighs of the chicken. Set aside for 30 minutes.
Rub the chicken with extra virgin olive oil, then arrange over a moderate barbecue grill and cook for 10 minutes, turning several times, until well-browned. Transfer to a rack over a baking tray then continue cooking. Stir the golden syrup into the remaining marinade, then begin basting the chicken every 5 minutes, until the chicken is firm to touch and glazed, about 35 minutes. Carve, then serve with cos, pickles, grilled flatbread and tzatziki.