Remove the excess fat from inside the bird. Put the chopped onion, crushed garlic and sliced lemon inside the bird. Boil the cider with the spices, pour over the bird and marinate for at least 4 hours, or overnight if that is simpler. Spoon over the marinade regularly, and ensure that there is plenty inside the bird. If you have refrigerated it ir taken it from a cold larder, let it stand to reach room temperature before cooking. Pour off the marinaade and keep it to one side, but leave the vegetables inside the bird.
Preheat the oven to Gas Mark 4/350 F/180 C.
Roast the goose on a rack in a pan for 15 minutes per pound (450g). It has a better and sweeter taste when still a little pink. During cooking, pour off the fat and reserve it, but do not baste the bird.
Brown the giblets in a little of the goose fat, add all of the marinade and cook over a medium heat for about 45 minutes, or until it is rich and starting to reduce. Strain through muslin or a very fine sieve, and keep warm.
Core the apples and score a line right round them through the skin, about one third from the top. Mix the almonds, saffron, orange flower water and currants together with a spoonful or more of the hot goose fat and stuff the apples.
Dribble more goose fat over the apples and bake in an ovenproof dish at the bottom of the oven for 30-45 minutes - they should be only just done when the goose is ready.
Once the goose is ready, take it from the pan and leave to stand, covered lightly, for at least 15 minutes, so that it sets nicely. Pour off the remaining fat from the pan and add any accumulated cooking juices to the giblets - marinade gravy, and reduce this further so that there are a few spoons of sauce per person.
A few minutes before you are ready to serve, carefully remove the top part of the cooked skin of the apples, revealing the white cooked pulp.
Mix the egg yolk with the extra saffron and the extra touch of sugar. Paint this mixture over the exposed apples and replace in the oven for just 5 or so minutes until set.
Whisk the 25-50g (1-2oz) butter onto the sauce over a medium heat.
Arrange the goose with its golden apples on a serving dish, pour the spiced sauce into a hot jug and take to your festive table.