Mix the hoisin sauce, soy sauce, honey, vinegar, sesame oil, garlic, ginger, tomato purée, and Chinese Five Spice Powder until smooth.
Coat the chicken thoroughly with the marinade and refrigerate for 1–2 hours, or overnight for the best flavour.
Preheat the oven to 200°C (180°C fan).
Heat the vegetable oil and sear the chicken until lightly golden.
Transfer to a roasting tin, brush with any remaining marinade, and roast until cooked through.
Cover loosely with foil halfway through cooking to keep the chicken juicy.
Rest for 15 minutes before slicing or carving.
Garnish with spring onions and sesame seeds.
Serve with rice pancakes, steamed jasmine rice, or stir-fried vegetables.