Heat the oven to 230ºC/210ºC fan/Gas 8. Remove and reserve the goose giblets for the gravy.
Sprinkle 1 tsp each of salt and pepper inside the goose cavity. Cut 2 onions and 2 apples into wedges and push these into the cavity with the lemon wedges and most of the rosemary and sage.
Put the goose breast-side up on a rack, resting in a roasting tin. Sprinkle over the rest of the seasoning and scatter with the remaining rosemary and sage sprigs. Cover completely with foil.
Work out the cooking time based on the size of your goose - 15 minutes per 450g (1lb) plus an extra 15 minutes. This recipe takes 3 hours for a 5kg (11lb) goose.
Roast the goose for 30 minutes, then reduce the oven temperature to Gas 5, 190ºC, fan 170ºC.
Using a sturdy stainless steel baster, suck up the fat at the base of the roasting tin after the first hour's cooking and reserve it in a heat proof container for future use (for example in the gravy or the roast potatoes recipes). Repeat again after another hour. Add the remaining onions and apples to the roasting pan for the final hour.
To test whether the goose is cooked, pierce the thigh with a skewer - it's ready when the juices run clear. Put the goose onto a large serving dish, with the onions and apples, re-cover with foil and leave to rest for 30 minutes before serving.
Some products in this recipe are seasonal and so may not be available to buy online all year.