Heat the oven to 220°C (425°F, gas mark 7). Put the onion, apple, prunes, liver and breadcrumbs in a bowl. Add the lemon zest, sage, almonds, salt and pepper and mix well.
Spoon the stuffing into the neck end of the goose, tuck the flap over it and secure with a skewer. Rub the skin with half the flour and sprinkle with salt and pepper. Place on a rack in a roasting tin and roast for 30 minutes.
Remove the goose from the oven and prick the skin all over with a fork. Reduce the oven to 180°C (350°F, gas mark 4) and roast for 1 3/4 to 2 hours until the juices run clear, draining off the fat several times during cooking.
Lift the goose on its rack from the tin and keep it warm. Skim the fat from the tin and stir in the remaining flour over a low heat. Whisk in the stock and Worcestershire sauce. Serve with boiled potatoes and a green vegetable.