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.