Pre-heat the oven to 200° C.
Arrange the onion and apples in the base of a roasting tray. Sit the pieces of chicken on top and dot with the butter. Season well, then pour the cider into the tray.
Roast for 40-50 minutes until the chicken is cooked through, the juices run clear when a skewer is inserted and the apples and onions are soft. Remove and spoon onto serving plates. Garnish with some more salt and black pepper and a sprig of sage before serving.
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.