Cover the chicken with a tent of foil and seal it tightly around the edges of the tin but don’t let the foil touch the skin. The water in the base of the tin will create steam during the first hour of roasting to keep the flesh super-moist.
For spiced roasties to serve with the chicken, reserve 1 tablespoon of the seasoning mix and sprinkle over 1.2kg par-boiled and drained potato chunks with 1/4 teaspoon salt. Heat 1 1/2 tablespoons vegetable oil in a shallow roasting tin and add the potatoes. Roast at 200°C (180°C for fan assisted ovens), gas mark 6 for 1 hour 15 minutes, turning once, until crisp and tender.